Move to gawk-2.15.3.

1 files changed, 0 insertions, 1173 deletions

diff --git a/gawk.info-8 b/gawk.info-8
deleted file mode 100644
index d0d693ff..00000000
--- a/gawk.info-8
+++ /dev/null
@@ -1,1173 +0,0 @@
-This is Info file gawk.info, produced by Makeinfo-1.54 from the input
-file gawk.texi.
-
-   This file documents `awk', a program that you can use to select
-particular records in a file and perform operations upon them.
-
-   This is Edition 0.15 of `The GAWK Manual',
-for the 2.15 version of the GNU implementation
-of AWK.
-
-   Copyright (C) 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
-
-   Permission is granted to make and distribute verbatim copies of this
-manual provided the copyright notice and this permission notice are
-preserved on all copies.
-
-   Permission is granted to copy and distribute modified versions of
-this manual under the conditions for verbatim copying, provided that
-the entire resulting derived work is distributed under the terms of a
-permission notice identical to this one.
-
-   Permission is granted to copy and distribute translations of this
-manual into another language, under the above conditions for modified
-versions, except that this permission notice may be stated in a
-translation approved by the Foundation.
-
-
-File: gawk.info,  Node: Regexp Summary,  Next: Actions Summary,  Prev: Pattern Summary,  Up: Rules Summary
-
-Regular Expressions
--------------------
-
-   Regular expressions are the extended kind found in `egrep'.  They
-are composed of characters as follows:
-
-`C'
-     matches the character C (assuming C is a character with no special
-     meaning in regexps).
-
-`\C'
-     matches the literal character C.
-
-`.'
-     matches any character except newline.
-
-`^'
-     matches the beginning of a line or a string.
-
-`$'
-     matches the end of a line or a string.
-
-`[ABC...]'
-     matches any of the characters ABC... (character class).
-
-`[^ABC...]'
-     matches any character except ABC... and newline (negated character
-     class).
-
-`R1|R2'
-     matches either R1 or R2 (alternation).
-
-`R1R2'
-     matches R1, and then R2 (concatenation).
-
-`R+'
-     matches one or more R's.
-
-`R*'
-     matches zero or more R's.
-
-`R?'
-     matches zero or one R's.
-
-`(R)'
-     matches R (grouping).
-
-   *Note Regular Expressions as Patterns: Regexp, for a more detailed
-explanation of regular expressions.
-
-   The escape sequences allowed in string constants are also valid in
-regular expressions (*note Constant Expressions: Constants.).
-
-
-File: gawk.info,  Node: Actions Summary,  Prev: Regexp Summary,  Up: Rules Summary
-
-Actions
--------
-
-   Action statements are enclosed in braces, `{' and `}'.  Action
-statements consist of the usual assignment, conditional, and looping
-statements found in most languages.  The operators, control statements,
-and input/output statements available are patterned after those in C.
-
-* Menu:
-
-* Operator Summary::            `awk' operators.
-* Control Flow Summary::        The control statements.
-* I/O Summary::                 The I/O statements.
-* Printf Summary::              A summary of `printf'.
-* Special File Summary::        Special file names interpreted internally.
-* Numeric Functions Summary::   Built-in numeric functions.
-* String Functions Summary::    Built-in string functions.
-* Time Functions Summary::      Built-in time functions.
-* String Constants Summary::    Escape sequences in strings.
-
-
-File: gawk.info,  Node: Operator Summary,  Next: Control Flow Summary,  Prev: Actions Summary,  Up: Actions Summary
-
-Operators
-.........
-
-   The operators in `awk', in order of increasing precedence, are:
-
-`= += -= *= /= %= ^='
-     Assignment.  Both absolute assignment (`VAR=VALUE') and operator
-     assignment (the other forms) are supported.
-
-`?:'
-     A conditional expression, as in C.  This has the form `EXPR1 ?
-     eXPR2 : EXPR3'.  If EXPR1 is true, the value of the expression is
-     EXPR2; otherwise it is EXPR3.  Only one of EXPR2 and EXPR3 is
-     evaluated.
-
-`||'
-     Logical "or".
-
-`&&'
-     Logical "and".
-
-`~ !~'
-     Regular expression match, negated match.
-
-`< <= > >= != =='
-     The usual relational operators.
-
-`BLANK'
-     String concatenation.
-
-`+ -'
-     Addition and subtraction.
-
-`* / %'
-     Multiplication, division, and modulus.
-
-`+ - !'
-     Unary plus, unary minus, and logical negation.
-
-`^'
-     Exponentiation (`**' may also be used, and `**=' for the assignment
-     operator, but they are not specified in the POSIX standard).
-
-`++ --'
-     Increment and decrement, both prefix and postfix.
-
-`$'
-     Field reference.
-
-   *Note Expressions as Action Statements: Expressions, for a full
-description of all the operators listed above.  *Note Examining Fields:
-Fields, for a description of the field reference operator.
-
-
-File: gawk.info,  Node: Control Flow Summary,  Next: I/O Summary,  Prev: Operator Summary,  Up: Actions Summary
-
-Control Statements
-..................
-
-   The control statements are as follows:
-
-     if (CONDITION) STATEMENT [ else STATEMENT ]
-     while (CONDITION) STATEMENT
-     do STATEMENT while (CONDITION)
-     for (EXPR1; EXPR2; EXPR3) STATEMENT
-     for (VAR in ARRAY) STATEMENT
-     break
-     continue
-     delete ARRAY[INDEX]
-     exit [ EXPRESSION ]
-     { STATEMENTS }
-
-   *Note Control Statements in Actions: Statements, for a full
-description of all the control statements listed above.
-
-
-File: gawk.info,  Node: I/O Summary,  Next: Printf Summary,  Prev: Control Flow Summary,  Up: Actions Summary
-
-I/O Statements
-..............
-
-   The input/output statements are as follows:
-
-`getline'
-     Set `$0' from next input record; set `NF', `NR', `FNR'.
-
-`getline <FILE'
-     Set `$0' from next record of FILE; set `NF'.
-
-`getline VAR'
-     Set VAR from next input record; set `NF', `FNR'.
-
-`getline VAR <FILE'
-     Set VAR from next record of FILE.
-
-`next'
-     Stop processing the current input record.  The next input record
-     is read and processing starts over with the first pattern in the
-     `awk' program.  If the end of the input data is reached, the `END'
-     rule(s), if any, are executed.
-
-`next file'
-     Stop processing the current input file.  The next input record
-     read comes from the next input file.  `FILENAME' is updated, `FNR'
-     is set to 1, and processing starts over with the first pattern in
-     the `awk' program.  If the end of the input data is reached, the
-     `END' rule(s), if any, are executed.
-
-`print'
-     Prints the current record.
-
-`print EXPR-LIST'
-     Prints expressions.
-
-`print EXPR-LIST > FILE'
-     Prints expressions on FILE.
-
-`printf FMT, EXPR-LIST'
-     Format and print.
-
-`printf FMT, EXPR-LIST > file'
-     Format and print on FILE.
-
-   Other input/output redirections are also allowed.  For `print' and
-`printf', `>> FILE' appends output to the FILE, and `| COMMAND' writes
-on a pipe.  In a similar fashion, `COMMAND | getline' pipes input into
-`getline'.  `getline' returns 0 on end of file, and -1 on an error.
-
-   *Note Explicit Input with `getline': Getline, for a full description
-of the `getline' statement.  *Note Printing Output: Printing, for a
-full description of `print' and `printf'.  Finally, *note The `next'
-Statement: Next Statement., for a description of how the `next'
-statement works.
-
-
-File: gawk.info,  Node: Printf Summary,  Next: Special File Summary,  Prev: I/O Summary,  Up: Actions Summary
-
-`printf' Summary
-................
-
-   The `awk' `printf' statement and `sprintf' function accept the
-following conversion specification formats:
-
-`%c'
-     An ASCII character.  If the argument used for `%c' is numeric, it
-     is treated as a character and printed.  Otherwise, the argument is
-     assumed to be a string, and the only first character of that
-     string is printed.
-
-`%d'
-`%i'
-     A decimal number (the integer part).
-
-`%e'
-     A floating point number of the form `[-]d.ddddddE[+-]dd'.
-
-`%f'
-     A floating point number of the form [`-']`ddd.dddddd'.
-
-`%g'
-     Use `%e' or `%f' conversion, whichever produces a shorter string,
-     with nonsignificant zeros suppressed.
-
-`%o'
-     An unsigned octal number (again, an integer).
-
-`%s'
-     A character string.
-
-`%x'
-     An unsigned hexadecimal number (an integer).
-
-`%X'
-     Like `%x', except use `A' through `F' instead of `a' through `f'
-     for decimal 10 through 15.
-
-`%%'
-     A single `%' character; no argument is converted.
-
-   There are optional, additional parameters that may lie between the
-`%' and the control letter:
-
-`-'
-     The expression should be left-justified within its field.
-
-`WIDTH'
-     The field should be padded to this width.  If WIDTH has a leading
-     zero, then the field is padded with zeros.  Otherwise it is padded
-     with blanks.
-
-`.PREC'
-     A number indicating the maximum width of strings or digits to the
-     right of the decimal point.
-
-   Either or both of the WIDTH and PREC values may be specified as `*'.
-In that case, the particular value is taken from the argument list.
-
-   *Note Using `printf' Statements for Fancier Printing: Printf, for
-examples and for a more detailed description.
-
-
-File: gawk.info,  Node: Special File Summary,  Next: Numeric Functions Summary,  Prev: Printf Summary,  Up: Actions Summary
-
-Special File Names
-..................
-
-   When doing I/O redirection from either `print' or `printf' into a
-file, or via `getline' from a file, `gawk' recognizes certain special
-file names internally.  These file names allow access to open file
-descriptors inherited from `gawk''s parent process (usually the shell).
-The file names are:
-
-`/dev/stdin'
-     The standard input.
-
-`/dev/stdout'
-     The standard output.
-
-`/dev/stderr'
-     The standard error output.
-
-`/dev/fd/N'
-     The file denoted by the open file descriptor N.
-
-   In addition the following files provide process related information
-about the running `gawk' program.
-
-`/dev/pid'
-     Reading this file returns the process ID of the current process,
-     in decimal, terminated with a newline.
-
-`/dev/ppid'
-     Reading this file returns the parent process ID of the current
-     process, in decimal, terminated with a newline.
-
-`/dev/pgrpid'
-     Reading this file returns the process group ID of the current
-     process, in decimal, terminated with a newline.
-
-`/dev/user'
-     Reading this file returns a single record terminated with a
-     newline.  The fields are separated with blanks.  The fields
-     represent the following information:
-
-    `$1'
-          The value of the `getuid' system call.
-
-    `$2'
-          The value of the `geteuid' system call.
-
-    `$3'
-          The value of the `getgid' system call.
-
-    `$4'
-          The value of the `getegid' system call.
-
-     If there are any additional fields, they are the group IDs
-     returned by `getgroups' system call.  (Multiple groups may not be
-     supported on all systems.)
-
-These file names may also be used on the command line to name data
-files.  These file names are only recognized internally if you do not
-actually have files by these names on your system.
-
-   *Note Standard I/O Streams: Special Files, for a longer description
-that provides the motivation for this feature.
-
-
-File: gawk.info,  Node: Numeric Functions Summary,  Next: String Functions Summary,  Prev: Special File Summary,  Up: Actions Summary
-
-Numeric Functions
-.................
-
-   `awk' has the following predefined arithmetic functions:
-
-`atan2(Y, X)'
-     returns the arctangent of Y/X in radians.
-
-`cos(EXPR)'
-     returns the cosine in radians.
-
-`exp(EXPR)'
-     the exponential function.
-
-`int(EXPR)'
-     truncates to integer.
-
-`log(EXPR)'
-     the natural logarithm function.
-
-`rand()'
-     returns a random number between 0 and 1.
-
-`sin(EXPR)'
-     returns the sine in radians.
-
-`sqrt(EXPR)'
-     the square root function.
-
-`srand(EXPR)'
-     use EXPR as a new seed for the random number generator.  If no EXPR
-     is provided, the time of day is used.  The return value is the
-     previous seed for the random number generator.
-
-
-File: gawk.info,  Node: String Functions Summary,  Next: Time Functions Summary,  Prev: Numeric Functions Summary,  Up: Actions Summary
-
-String Functions
-................
-
-   `awk' has the following predefined string functions:
-
-`gsub(R, S, T)'
-     for each substring matching the regular expression R in the string
-     T, substitute the string S, and return the number of substitutions.
-     If T is not supplied, use `$0'.
-
-`index(S, T)'
-     returns the index of the string T in the string S, or 0 if T is
-     not present.
-
-`length(S)'
-     returns the length of the string S.  The length of `$0' is
-     returned if no argument is supplied.
-
-`match(S, R)'
-     returns the position in S where the regular expression R occurs,
-     or 0 if R is not present, and sets the values of `RSTART' and
-     `RLENGTH'.
-
-`split(S, A, R)'
-     splits the string S into the array A on the regular expression R,
-     and returns the number of fields.  If R is omitted, `FS' is used
-     instead.
-
-`sprintf(FMT, EXPR-LIST)'
-     prints EXPR-LIST according to FMT, and returns the resulting
-     string.
-
-`sub(R, S, T)'
-     this is just like `gsub', but only the first matching substring is
-     replaced.
-
-`substr(S, I, N)'
-     returns the N-character substring of S starting at I.  If N is
-     omitted, the rest of S is used.
-
-`tolower(STR)'
-     returns a copy of the string STR, with all the upper-case
-     characters in STR translated to their corresponding lower-case
-     counterparts.  Nonalphabetic characters are left unchanged.
-
-`toupper(STR)'
-     returns a copy of the string STR, with all the lower-case
-     characters in STR translated to their corresponding upper-case
-     counterparts.  Nonalphabetic characters are left unchanged.
-
-`system(CMD-LINE)'
-     Execute the command CMD-LINE, and return the exit status.
-
-
-File: gawk.info,  Node: Time Functions Summary,  Next: String Constants Summary,  Prev: String Functions Summary,  Up: Actions Summary
-
-Built-in time functions
-.......................
-
-   The following two functions are available for getting the current
-time of day, and for formatting time stamps.
-
-`systime()'
-     returns the current time of day as the number of seconds since a
-     particular epoch (Midnight, January 1, 1970 UTC, on POSIX systems).
-
-`strftime(FORMAT, TIMESTAMP)'
-     formats TIMESTAMP according to the specification in FORMAT.  The
-     current time of day is used if no TIMESTAMP is supplied.  *Note
-     Functions for Dealing with Time Stamps: Time Functions, for the
-     details on the conversion specifiers that `strftime' accepts.
-
-
-File: gawk.info,  Node: String Constants Summary,  Prev: Time Functions Summary,  Up: Actions Summary
-
-String Constants
-................
-
-   String constants in `awk' are sequences of characters enclosed
-between double quotes (`"').  Within strings, certain "escape sequences"
-are recognized, as in C.  These are:
-
-`\\'
-     A literal backslash.
-
-`\a'
-     The "alert" character; usually the ASCII BEL character.
-
-`\b'
-     Backspace.
-
-`\f'
-     Formfeed.
-
-`\n'
-     Newline.
-
-`\r'
-     Carriage return.
-
-`\t'
-     Horizontal tab.
-
-`\v'
-     Vertical tab.
-
-`\xHEX DIGITS'
-     The character represented by the string of hexadecimal digits
-     following the `\x'.  As in ANSI C, all following hexadecimal
-     digits are considered part of the escape sequence.  (This feature
-     should tell us something about language design by committee.)
-     E.g., `"\x1B"' is a string containing the ASCII ESC (escape)
-     character.  (The `\x' escape sequence is not in POSIX `awk'.)
-
-`\DDD'
-     The character represented by the 1-, 2-, or 3-digit sequence of
-     octal digits.  Thus, `"\033"' is also a string containing the
-     ASCII ESC (escape) character.
-
-`\C'
-     The literal character C.
-
-   The escape sequences may also be used inside constant regular
-expressions (e.g., the regexp `/[ \t\f\n\r\v]/' matches whitespace
-characters).
-
-   *Note Constant Expressions: Constants.
-
-
-File: gawk.info,  Node: Functions Summary,  Next: Historical Features,  Prev: Rules Summary,  Up: Gawk Summary
-
-Functions
-=========
-
-   Functions in `awk' are defined as follows:
-
-     function NAME(PARAMETER LIST) { STATEMENTS }
-
-   Actual parameters supplied in the function call are used to
-instantiate the formal parameters declared in the function.  Arrays are
-passed by reference, other variables are passed by value.
-
-   If there are fewer arguments passed than there are names in
-PARAMETER-LIST, the extra names are given the null string as value.
-Extra names have the effect of local variables.
-
-   The open-parenthesis in a function call of a user-defined function
-must immediately follow the function name, without any intervening
-white space.  This is to avoid a syntactic ambiguity with the
-concatenation operator.
-
-   The word `func' may be used in place of `function' (but not in POSIX
-`awk').
-
-   Use the `return' statement to return a value from a function.
-
-   *Note User-defined Functions: User-defined, for a more complete
-description.
-
-
-File: gawk.info,  Node: Historical Features,  Prev: Functions Summary,  Up: Gawk Summary
-
-Historical Features
-===================
-
-   There are two features of historical `awk' implementations that
-`gawk' supports.  First, it is possible to call the `length' built-in
-function not only with no arguments, but even without parentheses!
-
-     a = length
-
-is the same as either of
-
-     a = length()
-     a = length($0)
-
-This feature is marked as "deprecated" in the POSIX standard, and
-`gawk' will issue a warning about its use if `-W lint' is specified on
-the command line.
-
-   The other feature is the use of the `continue' statement outside the
-body of a `while', `for', or `do' loop.  Traditional `awk'
-implementations have treated such usage as equivalent to the `next'
-statement.  `gawk' will support this usage if `-W posix' has not been
-specified.
-
-
-File: gawk.info,  Node: Sample Program,  Next: Bugs,  Prev: Gawk Summary,  Up: Top
-
-Sample Program
-**************
-
-   The following example is a complete `awk' program, which prints the
-number of occurrences of each word in its input.  It illustrates the
-associative nature of `awk' arrays by using strings as subscripts.  It
-also demonstrates the `for X in ARRAY' construction.  Finally, it shows
-how `awk' can be used in conjunction with other utility programs to do
-a useful task of some complexity with a minimum of effort.  Some
-explanations follow the program listing.
-
-     awk '
-     # Print list of word frequencies
-     {
-         for (i = 1; i <= NF; i++)
-             freq[$i]++
-     }
-     
-     END {
-         for (word in freq)
-             printf "%s\t%d\n", word, freq[word]
-     }'
-
-   The first thing to notice about this program is that it has two
-rules.  The first rule, because it has an empty pattern, is executed on
-every line of the input.  It uses `awk''s field-accessing mechanism
-(*note Examining Fields: Fields.) to pick out the individual words from
-the line, and the built-in variable `NF' (*note Built-in Variables::.)
-to know how many fields are available.
-
-   For each input word, an element of the array `freq' is incremented to
-reflect that the word has been seen an additional time.
-
-   The second rule, because it has the pattern `END', is not executed
-until the input has been exhausted.  It prints out the contents of the
-`freq' table that has been built up inside the first action.
-
-   Note that this program has several problems that would prevent it
-from being useful by itself on real text files:
-
-   * Words are detected using the `awk' convention that fields are
-     separated by whitespace and that other characters in the input
-     (except newlines) don't have any special meaning to `awk'.  This
-     means that punctuation characters count as part of words.
-
-   * The `awk' language considers upper and lower case characters to be
-     distinct.  Therefore, `foo' and `Foo' are not treated by this
-     program 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 that.
-
-   * The output does not come out in any useful order.  You're more
-     likely to be interested in which words occur most frequently, or
-     having an alphabetized table of how frequently each word occurs.
-
-   The way to solve these problems is to use some of the more advanced
-features of the `awk' language.  First, we use `tolower' to remove case
-distinctions.  Next, we use `gsub' to remove punctuation characters.
-Finally, we use the system `sort' utility to process the output of the
-`awk' script.  First, here is the new version of the program:
-
-     awk '
-     # Print list of word frequencies
-     {
-         $0 = tolower($0)    # remove case distinctions
-         gsub(/[^a-z0-9_ \t]/, "", $0)  # remove punctuation
-         for (i = 1; i <= NF; i++)
-             freq[$i]++
-     }
-     
-     END {
-         for (word in freq)
-             printf "%s\t%d\n", word, freq[word]
-     }'
-
-   Assuming we have saved this program in a file named `frequency.awk',
-and that the data is in `file1', the following pipeline
-
-     awk -f frequency.awk file1 | sort +1 -nr
-
-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' command and
-printed on the terminal.  The options given to `sort' in this example
-specify to sort using 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.
-
-   We could have even done the `sort' from within the program, by
-changing the `END' action to:
-
-     END {
-         sort = "sort +1 -nr"
-         for (word in freq)
-             printf "%s\t%d\n", word, freq[word] | sort
-         close(sort)
-     }'
-
-   See the general operating system documentation for more information
-on how to use the `sort' command.
-
-
-File: gawk.info,  Node: Bugs,  Next: Notes,  Prev: Sample Program,  Up: Top
-
-Reporting Problems and Bugs
-***************************
-
-   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
-what you're trying to do.  If it's not clear whether you should be able
-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
-reproduces the problem.  Then send us the program and data file, some
-idea of what kind of Unix system you're using, and the exact results
-`gawk' gave you.  Also say what you expected to occur; this will help
-us decide whether the problem was really in the documentation.
-
-   Once you have a precise problem, send e-mail to (Internet)
-`bug-gnu-utils@prep.ai.mit.edu' or (UUCP)
-`mit-eddie!prep.ai.mit.edu!bug-gnu-utils'.  Please include the version
-number of `gawk' you are using.  You can get this information with the
-command `gawk -W version '{}' /dev/null'.  You should send carbon
-copies of your mail to David Trueman at `david@cs.dal.ca', and to
-Arnold Robbins, who can be reached at `arnold@skeeve.atl.ga.us'.  David
-is most likely to fix code problems, while Arnold is most likely to fix
-documentation problems.
-
-   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 Arnold Robbins; he will try to help you out,
-although he may not have the time to fix the problem.  You can send him
-electronic mail at the Internet address above.
-
-   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 listed below, and also in the `README' file in the `gawk'
-distribution.  Information in the `README' file should be considered
-authoritative if it conflicts with this manual.
-
-   The people maintaining the non-Unix ports of `gawk' are:
-
-MS-DOS
-     The port to MS-DOS is maintained by Scott Deifik.  His electronic
-     mail address is `scottd@amgen.com'.
-
-VMS
-     The port to VAX VMS is maintained by Pat Rankin.  His electronic
-     mail address is `rankin@eql.caltech.edu'.
-
-Atari ST
-     The port to the Atari ST is maintained by Michal Jaegermann.  His
-     electronic mail address is `ntomczak@vm.ucs.ualberta.ca'.
-
-   If your bug is also reproducible under Unix, please send copies of
-your report to the general GNU bug list, as well as to Arnold Robbins
-and David Trueman, at the addresses listed above.
-
-
-File: gawk.info,  Node: Notes,  Next: Glossary,  Prev: Bugs,  Up: Top
-
-Implementation Notes
-********************
-
-   This appendix contains information mainly of interest to
-implementors and maintainers of `gawk'.  Everything in it applies
-specifically to `gawk', and not to other implementations.
-
-* Menu:
-
-* Compatibility Mode::          How to disable certain `gawk' extensions.
-* Future Extensions::           New features we may implement soon.
-* Improvements::                Suggestions for improvements by volunteers.
-
-
-File: gawk.info,  Node: Compatibility Mode,  Next: Future Extensions,  Prev: Notes,  Up: Notes
-
-Downward Compatibility and Debugging
-====================================
-
-   *Note Extensions in `gawk' not in POSIX `awk': 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 `-W
-compat' option, or with the `-W posix' option.
-
-   If `gawk' is compiled for debugging with `-DDEBUG', then there is
-one more option available on the command line:
-
-`-W parsedebug'
-     Print out the parse stack information as the program is being
-     parsed.
-
-   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.
-
-
-File: gawk.info,  Node: Future Extensions,  Next: Improvements,  Prev: Compatibility Mode,  Up: Notes
-
-Probable Future Extensions
-==========================
-
-   This section briefly lists extensions that indicate the directions
-we are currently considering for `gawk'.  The file `FUTURES' in the
-`gawk' distributions lists these extensions, as well as several others.
-
-`RS' as a regexp
-     The meaning of `RS' may be generalized along the lines of `FS'.
-
-Control of subprocess environment
-     Changes made in `gawk' to the array `ENVIRON' may be propagated to
-     subprocesses run by `gawk'.
-
-Databases
-     It may be possible to map a GDBM/NDBM/SDBM file into an `awk'
-     array.
-
-Single-character fields
-     The null string, `""', as a field separator, will cause field
-     splitting and the `split' function to separate individual
-     characters.  Thus, `split(a, "abcd", "")' would yield `a[1] ==
-     "a"', `a[2] == "b"', and so on.
-
-More `lint' warnings
-     There are more things that could be checked for portability.
-
-`RECLEN' variable for fixed length records
-     Along with `FIELDWIDTHS', this would speed up the processing of
-     fixed-length records.
-
-`RT' variable to hold the record terminator
-     It is occasionally useful to have access to the actual string of
-     characters that matched the `RS' variable.  The `RT' variable
-     would hold these characters.
-
-A `restart' keyword
-     After modifying `$0', `restart' would restart the pattern matching
-     loop, without reading a new record from the input.
-
-A `|&' redirection
-     The `|&' redirection, in place of `|', would open a two-way
-     pipeline for communication with a sub-process (via `getline' and
-     `print' and `printf').
-
-`IGNORECASE' affecting all comparisons
-     The effects of the `IGNORECASE' variable may be generalized to all
-     string comparisons, and not just regular expression operations.
-
-A way to mix command line source code and library files
-     There may be a new option that would make it possible to easily
-     use library functions from a program entered on the command line.
-
-GNU-style long options
-     We will add GNU-style long options to `gawk' for compatibility
-     with other GNU programs.  (For example, `--field-separator=:'
-     would be equivalent to `-F:'.)
-
-
-File: gawk.info,  Node: Improvements,  Prev: Future Extensions,  Up: Notes
-
-Suggestions for Improvements
-============================
-
-   Here are some projects that would-be `gawk' hackers might like to
-take on.  They vary in size from a few days to a few weeks of
-programming, depending on which one you choose and how fast a
-programmer you are.  Please send any improvements you write to the
-maintainers at the GNU project.
-
-  1. Compilation of `awk' programs: `gawk' uses a Bison (YACC-like)
-     parser to convert the script given it into a syntax tree; the
-     syntax tree is then executed by a simple recursive evaluator.
-     This method incurs a lot of overhead, since the recursive
-     evaluator performs many procedure calls to do even the simplest
-     things.
-
-     It should be possible for `gawk' to convert the script's parse tree
-     into a C program which the user would then compile, using the
-     normal C compiler and a special `gawk' library to provide all the
-     needed functions (regexps, fields, associative arrays, type
-     coercion, and so on).
-
-     An easier possibility might be for an intermediate phase of `awk'
-     to convert the parse tree into a linear byte code form like the
-     one used in GNU Emacs Lisp.  The recursive evaluator would then be
-     replaced by a straight line byte code interpreter that would be
-     intermediate in speed between running a compiled program and doing
-     what `gawk' does now.
-
-     This may actually happen for the 3.0 version of `gawk'.
-
-  2. An error message section has not been included in this version of
-     the manual.  Perhaps some nice beta testers will document some of
-     the messages for the future.
-
-  3. The programs in the test suite could use documenting in this
-     manual.
-
-  4. The programs and data files in the manual should be available in
-     separate files to facilitate experimentation.
-
-  5. See the `FUTURES' file for more ideas.  Contact us if you would
-     seriously like to tackle any of the items listed there.
-
-
-File: gawk.info,  Node: Glossary,  Next: Index,  Prev: Notes,  Up: Top
-
-Glossary
-********
-
-Action
-     A series of `awk' statements attached to a rule.  If the rule's
-     pattern matches an input record, the `awk' language executes the
-     rule's action.  Actions are always enclosed in curly braces.
-     *Note Overview of Actions: Actions.
-
-Amazing `awk' Assembler
-     Henry Spencer at the University of Toronto wrote a retargetable
-     assembler completely as `awk' scripts.  It is thousands of lines
-     long, including machine descriptions for several 8-bit
-     microcomputers.  It is a good example of a program that would have
-     been better written in another language.
-
-ANSI
-     The American National Standards Institute.  This organization
-     produces many standards, among them the standard for the C
-     programming language.
-
-Assignment
-     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".  *Note Assignment Expressions: Assignment Ops.
-
-`awk' Language
-     The language in which `awk' programs are written.
-
-`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'
-     programs may also contain function definitions.
-
-`awk' Script
-     Another name for an `awk' program.
-
-Built-in Function
-     The `awk' language provides built-in functions that perform various
-     numerical, time stamp related, and string computations.  Examples
-     are `sqrt' (for the square root of a number) and `substr' (for a
-     substring of a string).  *Note Built-in Functions: Built-in.
-
-Built-in Variable
-     `ARGC', `ARGIND', `ARGV', `CONVFMT', `ENVIRON', `ERRNO',
-     `FIELDWIDTHS', `FILENAME', `FNR', `FS', `IGNORECASE', `NF', `NR',
-     `OFMT', `OFS', `ORS', `RLENGTH', `RSTART', `RS', and `SUBSEP', are
-     the variables that have special meaning to `awk'.  Changing some
-     of them affects `awk''s running environment.  *Note Built-in
-     Variables::.
-
-Braces
-     See "Curly Braces."
-
-C
-     The system programming language that most GNU software is written
-     in.  The `awk' programming language has C-like syntax, and this
-     manual points out similarities between `awk' and C when
-     appropriate.
-
-CHEM
-     A preprocessor for `pic' that reads descriptions of molecules and
-     produces `pic' input for drawing them.  It was written by Brian
-     Kernighan, and is available from `netlib@research.att.com'.
-
-Compound Statement
-     A series of `awk' statements, enclosed in curly braces.  Compound
-     statements may be nested.  *Note Control Statements in Actions:
-     Statements.
-
-Concatenation
-     Concatenating two strings means sticking them together, one after
-     another, giving a new string.  For example, the string `foo'
-     concatenated with the string `bar' gives the string `foobar'.
-     *Note String Concatenation: Concatenation.
-
-Conditional Expression
-     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 Expressions:
-     Conditional Exp.
-
-Constant Regular Expression
-     A constant regular expression 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 doing its
-     execution.  *Note How to Use Regular Expressions: Regexp Usage.
-
-Comparison Expression
-     A relation that is either true or false, such as `(a < b)'.
-     Comparison expressions are used in `if', `while', and `for'
-     statements, and in patterns to select which input records to
-     process.  *Note Comparison Expressions: Comparison Ops.
-
-Curly Braces
-     The characters `{' and `}'.  Curly braces are used in `awk' for
-     delimiting actions, compound statements, and function bodies.
-
-Data Objects
-     These are numbers and strings of characters.  Numbers are
-     converted into strings and vice versa, as needed.  *Note
-     Conversion of Strings and Numbers: Conversion.
-
-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 may vary.
-     *Note How to Use Regular Expressions: Regexp Usage.
-
-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 Constant Expressions: Constants.
-
-Field
-     When `awk' reads an input record, it splits the record into pieces
-     separated by whitespace (or by a separator regexp which you can
-     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.  *Note
-     How Input is Split into Records: Records.
-
-Format
-     Format strings are used to control the appearance of output in the
-     `printf' statement.  Also, data conversions from numbers to strings
-     are controlled by the format string contained in the built-in
-     variable `CONVFMT'.  *Note Format-Control Letters: Control Letters.
-
-Function
-     A specialized group of statements often used to encapsulate general
-     or program-specific tasks.  `awk' has a number of built-in
-     functions, and also allows you to define your own.  *Note Built-in
-     Functions: Built-in.  Also, see *Note User-defined Functions:
-     User-defined.
-
-`gawk'
-     The GNU implementation of `awk'.
-
-GNU
-     "GNU's not Unix".  An on-going project of the Free Software
-     Foundation to create a complete, freely distributable,
-     POSIX-compliant computing environment.
-
-Input Record
-     A single chunk of data read in by `awk'.  Usually, an `awk' input
-     record consists of one line of text.  *Note How Input is Split
-     into Records: Records.
-
-Keyword
-     In the `awk' language, a keyword is a word that has special
-     meaning.  Keywords are reserved and may not be used as variable
-     names.
-
-     `awk''s keywords are: `if', `else', `while', `do...while', `for',
-     `for...in', `break', `continue', `delete', `next', `function',
-     `func', and `exit'.
-
-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
-     lvalue.
-
-Number
-     A numeric valued data object.  The `gawk' implementation uses
-     double precision floating point to represent numbers.
-
-Pattern
-     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 Patterns::.
-
-POSIX
-     The name for a series of standards being developed by the IEEE
-     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 P1003.2, the Command Language and
-     Utilities standard.
-
-Range (of input lines)
-     A sequence of consecutive lines from the input file.  A pattern
-     can specify ranges of input lines for `awk' to process, or it can
-     specify single lines.  *Note Patterns::.
-
-Recursion
-     When a function calls itself, either directly or indirectly.  If
-     this isn't clear, refer to the entry for "recursion."
-
-Redirection
-     Redirection means performing input from other than the standard
-     input stream, or output to other than the standard output stream.
-
-     You can redirect the output of the `print' and `printf' statements
-     to a file or a system command, using the `>', `>>', and `|'
-     operators.  You can redirect input to the `getline' statement using
-     the `<' and `|' operators.  *Note Redirecting Output of `print'
-     and `printf': Redirection.
-
-Regular Expression
-     See "regexp."
-
-Regexp
-     Short for "regular expression".  A regexp is a pattern that
-     denotes a set of strings, possibly an infinite set.  For example,
-     the regexp `R.*xp' matches any string starting with the letter `R'
-     and ending with the letters `xp'.  In `awk', regexps are used in
-     patterns and in conditional expressions.  Regexps may contain
-     escape sequences.  *Note Regular Expressions as Patterns: Regexp.
-
-Rule
-     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
-     action.  Otherwise, the rule does nothing for that input record.
-
-Side Effect
-     A side effect occurs when an expression has an effect aside from
-     merely producing a value.  Assignment expressions, increment
-     expressions and function calls have side effects.  *Note
-     Assignment Expressions: Assignment Ops.
-
-Special File
-     A file name interpreted internally by `gawk', instead of being
-     handed directly to the underlying operating system.  For example,
-     `/dev/stdin'.  *Note Standard I/O Streams: Special Files.
-
-Stream Editor
-     A program that reads records from an input stream and processes
-     them one or more at a time.  This is in contrast with batch
-     programs, which may expect to read their input files in entirety
-     before starting to do anything, and with interactive programs,
-     which require input from the user.
-
-String
-     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 Constant
-     Expressions: Constants.
-
-Whitespace
-     A sequence of blank or tab characters occurring inside an input
-     record or a string.
-