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diff --git a/doc/gawk.info b/doc/gawk.info index 664627c6..e11d3b06 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -382,6 +382,8 @@ in (a) below. A copy of the license is included in the section entitled * Arrays Summary:: Summary of arrays. * Built-in:: Summarizes the built-in functions. * Calling Built-in:: How to call built-in functions. +* Boolean Functions:: A function that returns Boolean + values. * Numeric Functions:: Functions that work with numbers, including 'int()', 'sin()' and 'rand()'. @@ -491,6 +493,7 @@ in (a) below. A copy of the license is included in the section entitled * Programs Summary:: Summary of programs. * Programs Exercises:: Exercises. * Nondecimal Data:: Allowing nondecimal input data. +* Boolean Typed Values:: Values with 'number|bool' type. * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Controlling Array Traversal:: How to use PROCINFO["sorted_in"]. @@ -554,6 +557,7 @@ in (a) below. A copy of the license is included in the section entitled * Inexact representation:: Numbers are not exactly represented. * Comparing FP Values:: How to compare floating point values. * Errors accumulate:: Errors get bigger as they go. +* Strange values:: A few words about infinities and NaNs. * Getting Accuracy:: Getting more accuracy takes some work. * Try To Round:: Add digits and round. * Setting precision:: How to set the precision. @@ -3227,7 +3231,9 @@ change. The variables are: '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. + With a value of 'fnv1a', 'gawk' uses the FNV1-A hash function + (http://www.isthe.com/chongo/tech/comp/fnv/index.html). These + functions may be marginally faster than the standard function. 'AWKREADFUNC' If this variable exists, 'gawk' switches to reading source files @@ -7024,8 +7030,8 @@ 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' or 'infinity'. The - special "not a number" value formats as '-nan' or 'nan' (*note Math - Definitions::). + special "not a number" value formats as '-nan' or 'nan' (*note + Strange values::). '%F' Like '%f', but the infinity and "not a number" values are spelled @@ -12862,6 +12868,7 @@ your convenience. * Menu: * Calling Built-in:: How to call built-in functions. +* Boolean Functions:: A function that returns Boolean values. * Numeric Functions:: Functions that work with numbers, including 'int()', 'sin()' and 'rand()'. * String Functions:: Functions for string manipulation, such as @@ -12874,7 +12881,7 @@ your convenience. * I18N Functions:: Functions for string translation. -File: gawk.info, Node: Calling Built-in, Next: Numeric Functions, Up: Built-in +File: gawk.info, Node: Calling Built-in, Next: Boolean Functions, Up: Built-in 9.1.1 Calling Built-in Functions -------------------------------- @@ -12918,9 +12925,24 @@ six, and then 12, and 'atan2()' is called with the two arguments six and 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 +File: gawk.info, Node: Boolean Functions, Next: Numeric Functions, Prev: Calling Built-in, Up: Built-in -9.1.2 Numeric Functions +9.1.2 Generating Boolean Values +------------------------------- + +This function is specific to 'gawk'. It is not available in +compatibility mode (*note Options::): + +'mkbool(EXPRESSION)' + Return a Boolean-typed value based on the regular Boolean value of + EXPRESSION. Boolean "true" values have numeric value one. Boolean + "false" values have numeric zero. This is discussed in more detail + in *note Boolean Typed Values::. + + +File: gawk.info, Node: Numeric Functions, Next: String Functions, Prev: Boolean Functions, Up: Built-in + +9.1.3 Numeric Functions ----------------------- The following list describes all of the built-in functions that work @@ -12946,7 +12968,7 @@ brackets ([ ]): 'log(X)' Return the natural logarithm of X, if X is positive; otherwise, - return 'NaN' ("not a number") on IEEE 754 systems. Additionally, + return NaN ("not a number") on IEEE 754 systems. Additionally, 'gawk' prints a warning message when 'x' is negative. 'rand()' @@ -13044,7 +13066,7 @@ 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 -9.1.3 String-Manipulation Functions +9.1.4 String-Manipulation Functions ----------------------------------- The functions in this minor node look at or change the text of one or @@ -13629,7 +13651,7 @@ number zero. File: gawk.info, Node: Gory Details, Up: String Functions -9.1.3.1 More about '\' and '&' with 'sub()', 'gsub()', and 'gensub()' +9.1.4.1 More about '\' and '&' with 'sub()', 'gsub()', and 'gensub()' ..................................................................... CAUTION: This subsubsection has been reported to cause headaches. @@ -13779,7 +13801,7 @@ POSIX rules. File: gawk.info, Node: I/O Functions, Next: Time Functions, Prev: String Functions, Up: Built-in -9.1.4 Input/Output Functions +9.1.5 Input/Output Functions ---------------------------- The following functions relate to input/output (I/O). Optional @@ -13997,7 +14019,7 @@ the way this was done was probably a mistake. File: gawk.info, Node: Time Functions, Next: Bitwise Functions, Prev: I/O Functions, Up: Built-in -9.1.5 Time Functions +9.1.6 Time Functions -------------------- 'awk' programs are commonly used to process log files containing @@ -14314,7 +14336,7 @@ does not appear in the returned string or appears literally. File: gawk.info, Node: Bitwise Functions, Next: Type Functions, Prev: Time Functions, Up: Built-in -9.1.6 Bit-Manipulation Functions +9.1.7 Bit-Manipulation Functions -------------------------------- I can explain it for you, but I can't understand it for you. @@ -14497,7 +14519,7 @@ that range are reduced to fit within the range. File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Functions, Up: Built-in -9.1.7 Getting Type Information +9.1.8 Getting Type Information ------------------------------ 'gawk' provides two functions that let you distinguish the type of a @@ -14521,6 +14543,9 @@ contexts. '"number"' X is a number. + '"number|bool"' + X is a Boolean typed value (*note Boolean Typed Values::). + '"string"' X is a string. @@ -14595,7 +14620,7 @@ different, they are automatically forced to be scalars. Consider: File: gawk.info, Node: I18N Functions, Prev: Type Functions, Up: Built-in -9.1.8 String-Translation Functions +9.1.9 String-Translation Functions ---------------------------------- 'gawk' provides facilities for internationalizing 'awk' programs. These @@ -15274,7 +15299,7 @@ File: gawk.info, Node: Indirect Calls, Next: Functions Summary, Prev: User-de 9.3 Indirect Function Calls =========================== -This section describes an advanced, 'gawk'-specific extension. +This minor node 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 @@ -21028,6 +21053,7 @@ their own: * Menu: * Nondecimal Data:: Allowing nondecimal input data. +* Boolean Typed Values:: Values with 'number|bool' type. * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Two-way I/O:: Two-way communications with another process. @@ -21037,7 +21063,7 @@ their own: * Advanced Features Summary:: Summary of advanced features. -File: gawk.info, Node: Nondecimal Data, Next: Array Sorting, Up: Advanced Features +File: gawk.info, Node: Nondecimal Data, Next: Boolean Typed Values, Up: Advanced Features 12.1 Allowing Nondecimal Input Data =================================== @@ -21080,9 +21106,53 @@ request it. This option may disappear in a future version of 'gawk'. -File: gawk.info, Node: Array Sorting, Next: Two-way I/O, Prev: Nondecimal Data, Up: Advanced Features +File: gawk.info, Node: Boolean Typed Values, Next: Array Sorting, Prev: Nondecimal Data, Up: Advanced Features + +12.2 Boolean Typed Values +========================= + +Scalar values in 'awk' are either numbers or strings. 'gawk' also +supports values of type 'regexp' (*note Strong Regexp Constants::). + + As described in *note Truth Values::, Boolean values in 'awk' don't +have a separate type: a value counts as "true" if it is nonzero or +non-null, and as "false" otherwise. + + When interchanging data with languages that do have a real Boolean +type, using a standard format such as JSON or XML, the lack of a true +Boolean type in 'awk' is problematic. (See, for example, the 'json' +extension provided by the 'gawkextlib' project +(https://sourceforge.net/projects/gawkextlib).) + + It's easy to import Boolean data into 'awk', but then the fact that +it was originally Boolean is lost. Exporting data is even harder; +there's no way to indicate that a value is really Boolean. + + To solve this problem, 'gawk' provides a function named 'mkbool()'. +It takes one argument, which is any 'awk' expression, and it returns a +value of Boolean type. + + The returned values are normal 'awk' numeric values, with values of +either one or zero, depending upon the truth value of the original +expression passed in the call to 'mkbool()'. + + The 'typeof()' function (*note Type Functions::) returns +'"number|bool"' for these values. + + Thus Boolean-typed values _are_ numbers as far as 'gawk' is +concerned, except that extension code can treat them as Booleans if +desired. + + While it would have been possible to add two new built-in variables +of Boolean type named 'TRUE' and 'FALSE', doing so would undoubtedly +have broken many existing 'awk' programs. Instead, having a "generator" +function that creates Boolean values gives flexibility, without breaking +as much existing code. + + +File: gawk.info, Node: Array Sorting, Next: Two-way I/O, Prev: Boolean Typed Values, Up: Advanced Features -12.2 Controlling Array Traversal and Array Sorting +12.3 Controlling Array Traversal and Array Sorting ================================================== 'gawk' lets you control the order in which a 'for (INDX in ARRAY)' loop @@ -21101,7 +21171,7 @@ to order the elements during sorting. File: gawk.info, Node: Controlling Array Traversal, Next: Array Sorting Functions, Up: Array Sorting -12.2.1 Controlling Array Traversal +12.3.1 Controlling Array Traversal ---------------------------------- By default, the order in which a 'for (INDX in ARRAY)' loop scans an @@ -21340,7 +21410,7 @@ character, which cannot be part of an identifier. File: gawk.info, Node: Array Sorting Functions, Prev: Controlling Array Traversal, Up: Array Sorting -12.2.2 Sorting Array Values and Indices with 'gawk' +12.3.2 Sorting Array Values and Indices with 'gawk' --------------------------------------------------- In most 'awk' implementations, sorting an array requires writing a @@ -21485,7 +21555,7 @@ POSIX-compatibility mode, and because 'asort()' and 'asorti()' are File: gawk.info, Node: Two-way I/O, Next: TCP/IP Networking, Prev: Array Sorting, Up: Advanced Features -12.3 Two-Way Communications with Another Process +12.4 Two-Way Communications with Another Process ================================================ It is often useful to be able to send data to a separate program for @@ -21680,7 +21750,7 @@ 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 +12.5 Using 'gawk' for Network Programming ========================================= 'EMRED': @@ -21760,7 +21830,7 @@ well as extensive examples. File: gawk.info, Node: Profiling, Next: Extension Philosophy, Prev: TCP/IP Networking, Up: Advanced Features -12.5 Profiling Your 'awk' Programs +12.6 Profiling Your 'awk' Programs ================================== You may produce execution traces of your 'awk' programs. This is done @@ -22022,7 +22092,7 @@ source code, it will appear that way in the output. File: gawk.info, Node: Extension Philosophy, Next: Advanced Features Summary, Prev: Profiling, Up: Advanced Features -12.6 Builtin Features versus Extensions +12.7 Builtin Features versus Extensions ======================================= As this and subsequent major nodes show, 'gawk' has a large number of @@ -22058,7 +22128,7 @@ or need. File: gawk.info, Node: Advanced Features Summary, Prev: Extension Philosophy, Up: Advanced Features -12.7 Summary +12.8 Summary ============ * The '--non-decimal-data' option causes 'gawk' to treat octal- and @@ -24417,18 +24487,10 @@ material here: another number and infinity produce infinity. "NaN" - "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'. + "Not a number." A special value that results from attempting a + calculation that has no answer as a real number. *Note Strange + values::, for more information about infinity and not-a-number + values. "Normalized" How the significand (see later in this list) is usually stored. @@ -24488,11 +24550,6 @@ Table 16.3: Basic IEEE format 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 we have -paraphrased, and for the examples. - File: gawk.info, Node: MPFR features, Next: FP Math Caution, Prev: Math Definitions, Up: Arbitrary Precision Arithmetic @@ -24585,6 +24642,7 @@ be sure of the number of significant decimal places in the final result. * Inexact representation:: Numbers are not exactly represented. * Comparing FP Values:: How to compare floating point values. * Errors accumulate:: Errors get bigger as they go. +* Strange values:: A few words about infinities and NaNs. File: gawk.info, Node: Inexact representation, Next: Comparing FP Values, Up: Inexactness of computations @@ -24649,7 +24707,7 @@ values with a delta, you should be sure to use 'difference < abs(delta)' in case someone passes in a negative delta value. -File: gawk.info, Node: Errors accumulate, Prev: Comparing FP Values, Up: Inexactness of computations +File: gawk.info, Node: Errors accumulate, Next: Strange values, Prev: Comparing FP Values, Up: Inexactness of computations 16.4.1.3 Errors Accumulate .......................... @@ -24697,6 +24755,64 @@ representations yield an unexpected result: -| 4 +File: gawk.info, Node: Strange values, Prev: Errors accumulate, Up: Inexactness of computations + +16.4.1.4 Floating Point Values They Didn't Talk About In School +............................................................... + +Both IEEE 754 floating-point hardware, and MPFR, support two kinds of +values that you probably didn't learn about in school. The first is +"infinity", a special value, that can be either negative or positive, +and which is either smaller than any other value (negative infinity), or +larger than any other value (positive infinity). When such values are +generated, 'gawk' prints them as either '-inf' or '+inf', respectively. +It accepts those strings as data input and converts them to the proper +floating-point values internally. + + Infinity values of the same sign compare as equal to each other. +Otherwise, operations (addition, subtraction, etc.) involving another +number and infinity produce mathematically reasonable results. + + The second kind of value is "not a number", or NaN for short.(1) +This is 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. + + NaN values are strange. In particular, they cannot be compared with +other floating point values; any such comparison, except for "is not +equal to", returns false. NaN values are so much unequal to other +values that even comparing two identical NaN values with '!=' returns +true! + + NaN values can also be signed, although it depends upon the +implementation as to which sign you get for any operation that returns a +NaN. For example, on some systems, 'sqrt(-1)' returns a negative NaN. On +others, it returns a positive NaN. + + When such values are generated, 'gawk' prints them as either '-nan' +or '+nan', respectively. Here too, 'gawk' accepts those strings as data +input and converts them to the proper floating-point values internally. + + If you want to dive more deeply into this topic, you can find test +programs in C, 'awk' and Python in the directory +'awklib/eg/test-programs' in the 'gawk' distribution. These programs +enable comparison among programming languages as to how they handle NaN +and infinity values. + + ---------- Footnotes ---------- + + (1) Thanks to Michael Brennan for this description, which we have +paraphrased, and for the examples. + + File: gawk.info, Node: Getting Accuracy, Next: Try To Round, Prev: Inexactness of computations, Up: FP Math Caution 16.4.2 Getting the Accuracy You Need @@ -25649,7 +25765,8 @@ use them. ' AWK_STRNUM,' ' AWK_ARRAY,' ' AWK_SCALAR, /* opaque access to a variable */' -' AWK_VALUE_COOKIE /* for updating a previously created value */' +' AWK_VALUE_COOKIE, /* for updating a previously created value */' +' AWK_BOOL' '} awk_valtype_t;' This 'enum' indicates the type of a value. It is used in the following 'struct'. @@ -25662,6 +25779,7 @@ use them. ' awk_array_t a;' ' awk_scalar_t scl;' ' awk_value_cookie_t vc;' +' awk_bool_t b;' ' } u;' '} awk_value_t;' An "'awk' value." The 'val_type' member indicates what kind of @@ -25677,6 +25795,7 @@ use them. '#define array_cookie u.a' '#define scalar_cookie u.scl' '#define value_cookie u.vc' +'#define bool_value u.b' Using these macros makes accessing the fields of the 'awk_value_t' more readable. @@ -25987,6 +26106,11 @@ code would use them: a 'char *' value pointing to data previously obtained from 'gawk_malloc()', 'gawk_calloc()', or 'gawk_realloc()'. +'static inline awk_value_t *' +'make_bool(awk_bool_t boolval, awk_value_t *result);' + This function creates a boolean value in the 'awk_value_t' variable + pointed to by 'result'. + File: gawk.info, Node: API Ownership of MPFR and GMP Values, Next: Registration Functions, Prev: Constructor Functions, Up: Extension API Description @@ -26713,16 +26837,17 @@ summarized in *note Table 17.2: table-value-types-returned. Type of Actual Value -------------------------------------------------------------------------- - String Strnum Number Regex Array Undefined -------------------------------------------------------------------------------- - String String String String String false false - Strnum false Strnum Strnum false false false - Number Number Number Number false false false -Type Regex false false false Regex false false -Requested Array false false false false Array false - Scalar Scalar Scalar Scalar Scalar false false - Undefined String Strnum Number Regex Array Undefined - Value false false false false false false + String Strnum Number Regex Bool Array Undefined +---------------------------------------------------------------------------------------- + String String String String String String false false + Strnum false Strnum Strnum false false false false + Number Number Number Number false Number false false +Type Regex false false false Regex false false false +Requested Bool false false false false Bool false false + Array false false false false false Array false + Scalar Scalar Scalar Scalar Scalar Scalar false false + Undefined String Strnum Number Regex Bool Array Undefined + Value false false false false false false false cookie Table 17.2: API value types returned @@ -33615,8 +33740,8 @@ Localization Logical Expression An expression using the operators for logic, AND, OR, and NOT, - written '&&', '||', and '!' in 'awk'. Often called Boolean - expressions, after the mathematician who pioneered this kind of + written '&&', '||', and '!' in 'awk'. Often called "Boolean + expressions", after the mathematician who pioneered this kind of mathematical logic. Lvalue @@ -35774,6 +35899,7 @@ Index * body, in loops: While Statement. (line 14) * Boolean expressions: Boolean Ops. (line 6) * Boolean expressions, as patterns: Expression Patterns. (line 39) +* boolean function: Boolean Functions. (line 6) * Bourne shell, quoting rules for: Quoting. (line 18) * braces ({}), regexp operator: Regexp Operator Details. (line 118) @@ -36130,7 +36256,7 @@ Index * dark corner, length() function: String Functions. (line 200) * dark corner, split() function: String Functions. (line 379) * dark corner, array elements created by reference: Type Functions. - (line 85) + (line 88) * dark corner, parameter name restrictions: Definition Syntax. (line 44) * dark corner <1>: Glossary. (line 266) @@ -37371,6 +37497,7 @@ Index * metacharacters, in regular expressions: Regexp Operators. (line 6) * minimum precision required by MPFR library: Auto-set. (line 279) * Minshall, Greg: Getopt Function. (line 105) +* mkbool: Boolean Functions. (line 10) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * module, definition of: Global Namespace. (line 18) @@ -38598,610 +38725,613 @@ Index Tag Table: Node: Top1200 -Node: Foreword345313 -Node: Foreword449755 -Node: Preface51287 -Ref: Preface-Footnote-154146 -Ref: Preface-Footnote-254255 -Ref: Preface-Footnote-354489 -Node: History54631 -Node: Names56983 -Ref: Names-Footnote-158087 -Node: This Manual58234 -Ref: This Manual-Footnote-164873 -Node: Conventions64973 -Node: Manual History67342 -Ref: Manual History-Footnote-170339 -Ref: Manual History-Footnote-270380 -Node: How To Contribute70454 -Node: Acknowledgments71380 -Node: Getting Started76317 -Node: Running gawk78756 -Node: One-shot79946 -Node: Read Terminal81209 -Node: Long83202 -Node: Executable Scripts84715 -Ref: Executable Scripts-Footnote-187348 -Node: Comments87451 -Node: Quoting89935 -Node: DOS Quoting95461 -Node: Sample Data Files97517 -Node: Very Simple100112 -Node: Two Rules106214 -Node: More Complex108099 -Node: Statements/Lines110431 -Ref: Statements/Lines-Footnote-1114915 -Node: Other Features115180 -Node: When116116 -Ref: When-Footnote-1117870 -Node: Intro Summary117935 -Node: Invoking Gawk118819 -Node: Command Line120333 -Node: Options121131 -Ref: Options-Footnote-1139045 -Ref: Options-Footnote-2139276 -Node: Other Arguments139301 -Node: Naming Standard Input143312 -Node: Environment Variables144522 -Node: AWKPATH Variable145080 -Ref: AWKPATH Variable-Footnote-1148492 -Ref: AWKPATH Variable-Footnote-2148526 -Node: AWKLIBPATH Variable148897 -Ref: AWKLIBPATH Variable-Footnote-1150594 -Node: Other Environment Variables150969 -Node: Exit Status154790 -Node: Include Files155467 -Node: Loading Shared Libraries159157 -Node: Obsolete160585 -Node: Undocumented161277 -Node: Invoking Summary161574 -Node: Regexp164415 -Node: Regexp Usage165869 -Node: Escape Sequences167906 -Node: Regexp Operators174147 -Node: Regexp Operator Details174632 -Ref: Regexp Operator Details-Footnote-1181996 -Node: Interval Expressions182143 -Ref: Interval Expressions-Footnote-1184343 -Node: Bracket Expressions184441 -Ref: table-char-classes186917 -Node: Leftmost Longest190244 -Node: Computed Regexps191547 -Node: GNU Regexp Operators194974 -Node: Case-sensitivity198711 -Ref: Case-sensitivity-Footnote-1201577 -Ref: Case-sensitivity-Footnote-2201812 -Node: Regexp Summary201920 -Node: Reading Files203386 -Node: Records205655 -Node: awk split records206730 -Node: gawk split records211430 -Ref: gawk split records-Footnote-1216504 -Node: Fields216541 -Node: Nonconstant Fields219282 -Ref: Nonconstant Fields-Footnote-1221518 -Node: Changing Fields221722 -Node: Field Separators227753 -Node: Default Field Splitting230451 -Node: Regexp Field Splitting231569 -Node: Single Character Fields235246 -Node: Command Line Field Separator236306 -Node: Full Line Fields239524 -Ref: Full Line Fields-Footnote-1241046 -Ref: Full Line Fields-Footnote-2241092 -Node: Field Splitting Summary241193 -Node: Constant Size243267 -Node: Fixed width data243999 -Node: Skipping intervening247466 -Node: Allowing trailing data248264 -Node: Fields with fixed data249301 -Node: Splitting By Content250819 -Ref: Splitting By Content-Footnote-1254655 -Node: More CSV254818 -Node: FS versus FPAT256433 -Node: Testing field creation257593 -Node: Multiple Line259218 -Node: Getline265495 -Node: Plain Getline267964 -Node: Getline/Variable270537 -Node: Getline/File271688 -Node: Getline/Variable/File273076 -Ref: Getline/Variable/File-Footnote-1274681 -Node: Getline/Pipe274769 -Node: Getline/Variable/Pipe277473 -Node: Getline/Coprocess278608 -Node: Getline/Variable/Coprocess279875 -Node: Getline Notes280617 -Node: Getline Summary283414 -Ref: table-getline-variants283838 -Node: Read Timeout284587 -Ref: Read Timeout-Footnote-1288493 -Node: Retrying Input288551 -Node: Command-line directories289750 -Node: Input Summary290656 -Node: Input Exercises293828 -Node: Printing294262 -Node: Print296096 -Node: Print Examples297553 -Node: Output Separators300333 -Node: OFMT302350 -Node: Printf303706 -Node: Basic Printf304491 -Node: Control Letters306065 -Node: Format Modifiers311229 -Node: Printf Examples317244 -Node: Redirection319730 -Node: Special FD326571 -Ref: Special FD-Footnote-1329739 -Node: Special Files329813 -Node: Other Inherited Files330430 -Node: Special Network331431 -Node: Special Caveats332291 -Node: Close Files And Pipes333240 -Ref: table-close-pipe-return-values340147 -Ref: Close Files And Pipes-Footnote-1340961 -Ref: Close Files And Pipes-Footnote-2341109 -Node: Nonfatal341261 -Node: Output Summary343599 -Node: Output Exercises344821 -Node: Expressions345500 -Node: Values346688 -Node: Constants347366 -Node: Scalar Constants348057 -Ref: Scalar Constants-Footnote-1350567 -Node: Nondecimal-numbers350817 -Node: Regexp Constants353818 -Node: Using Constant Regexps354344 -Node: Standard Regexp Constants354966 -Node: Strong Regexp Constants358154 -Node: Variables361869 -Node: Using Variables362526 -Node: Assignment Options364436 -Node: Conversion366907 -Node: Strings And Numbers367431 -Ref: Strings And Numbers-Footnote-1370494 -Node: Locale influences conversions370603 -Ref: table-locale-affects373361 -Node: All Operators373980 -Node: Arithmetic Ops374609 -Node: Concatenation377325 -Ref: Concatenation-Footnote-1380172 -Node: Assignment Ops380279 -Ref: table-assign-ops385270 -Node: Increment Ops386584 -Node: Truth Values and Conditions390044 -Node: Truth Values391118 -Node: Typing and Comparison392166 -Node: Variable Typing392986 -Ref: Variable Typing-Footnote-1399449 -Ref: Variable Typing-Footnote-2399521 -Node: Comparison Operators399598 -Ref: table-relational-ops400017 -Node: POSIX String Comparison403513 -Ref: POSIX String Comparison-Footnote-1405208 -Ref: POSIX String Comparison-Footnote-2405347 -Node: Boolean Ops405431 -Ref: Boolean Ops-Footnote-1409913 -Node: Conditional Exp410005 -Node: Function Calls411741 -Node: Precedence415618 -Node: Locales419277 -Node: Expressions Summary420909 -Node: Patterns and Actions423482 -Node: Pattern Overview424602 -Node: Regexp Patterns426279 -Node: Expression Patterns426821 -Node: Ranges430602 -Node: BEGIN/END433710 -Node: Using BEGIN/END434471 -Ref: Using BEGIN/END-Footnote-1437225 -Node: I/O And BEGIN/END437331 -Node: BEGINFILE/ENDFILE439644 -Node: Empty442875 -Node: Using Shell Variables443192 -Node: Action Overview445466 -Node: Statements447791 -Node: If Statement449639 -Node: While Statement451134 -Node: Do Statement453162 -Node: For Statement454310 -Node: Switch Statement457565 -Node: Break Statement460006 -Node: Continue Statement462098 -Node: Next Statement463925 -Node: Nextfile Statement466308 -Node: Exit Statement468997 -Node: Built-in Variables471400 -Node: User-modified472533 -Node: Auto-set480300 -Ref: Auto-set-Footnote-1497107 -Ref: Auto-set-Footnote-2497313 -Node: ARGC and ARGV497369 -Node: Pattern Action Summary501582 -Node: Arrays504012 -Node: Array Basics505341 -Node: Array Intro506185 -Ref: figure-array-elements508160 -Ref: Array Intro-Footnote-1510865 -Node: Reference to Elements510993 -Node: Assigning 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Functions Summary733937 +Node: Library Exercises735343 +Node: Sample Programs735808 +Node: Running Examples736578 +Node: Clones737306 +Node: Cut Program738530 +Node: Egrep Program748670 +Node: Id Program757671 +Node: Split Program767606 +Ref: Split Program-Footnote-1777499 +Node: Tee Program777672 +Node: Uniq Program780462 +Node: Wc Program788050 +Node: Bytes vs. Characters788437 +Node: Using extensions789985 +Node: wc program790739 +Node: Miscellaneous Programs795604 +Node: Dupword Program796817 +Node: Alarm Program798847 +Node: Translate Program803702 +Ref: Translate Program-Footnote-1808267 +Node: Labels Program808537 +Ref: Labels Program-Footnote-1811888 +Node: Word Sorting811972 +Node: History Sorting816044 +Node: Extract Program818269 +Node: Simple Sed826282 +Node: Igawk Program829356 +Ref: Igawk Program-Footnote-1843687 +Ref: Igawk Program-Footnote-2843889 +Ref: Igawk Program-Footnote-3844011 +Node: Anagram Program844126 +Node: Signature Program847188 +Node: Programs Summary848435 +Node: Programs Exercises849649 +Ref: Programs Exercises-Footnote-1853779 +Node: Advanced Features853865 +Node: Nondecimal Data855996 +Node: Boolean Typed Values857594 +Node: Array Sorting859475 +Node: Controlling Array Traversal860180 +Ref: Controlling Array Traversal-Footnote-1868548 +Node: Array Sorting Functions868666 +Ref: Array Sorting Functions-Footnote-1874040 +Node: Two-way I/O874236 +Ref: Two-way I/O-Footnote-1881962 +Ref: Two-way I/O-Footnote-2882149 +Node: TCP/IP Networking882231 +Node: Profiling885307 +Node: Extension Philosophy894616 +Node: Advanced Features Summary896095 +Node: Internationalization898110 +Node: I18N and L10N899784 +Node: Explaining gettext900471 +Ref: Explaining gettext-Footnote-1906363 +Ref: Explaining gettext-Footnote-2906548 +Node: Programmer i18n906713 +Ref: Programmer i18n-Footnote-1911662 +Node: Translator i18n911711 +Node: String Extraction912505 +Ref: String Extraction-Footnote-1913637 +Node: Printf Ordering913723 +Ref: Printf Ordering-Footnote-1916509 +Node: I18N Portability916573 +Ref: I18N Portability-Footnote-1919029 +Node: I18N Example919092 +Ref: I18N Example-Footnote-1922367 +Ref: I18N Example-Footnote-2922440 +Node: Gawk I18N922549 +Node: I18N Summary923171 +Node: Debugger924512 +Node: Debugging925512 +Node: Debugging Concepts925953 +Node: Debugging Terms927762 +Node: Awk Debugging930337 +Ref: Awk Debugging-Footnote-1931282 +Node: Sample Debugging Session931414 +Node: Debugger Invocation931948 +Node: Finding The Bug933334 +Node: List of Debugger Commands939808 +Node: Breakpoint Control941141 +Node: Debugger Execution Control944835 +Node: Viewing And Changing Data948197 +Node: Execution Stack951738 +Node: Debugger Info953375 +Node: Miscellaneous Debugger Commands957446 +Node: Readline Support962508 +Node: Limitations963404 +Node: Debugging Summary965958 +Node: Namespaces967237 +Node: Global Namespace968348 +Node: Qualified Names969746 +Node: Default Namespace970745 +Node: Changing The Namespace971486 +Node: Naming Rules973100 +Node: Internal Name Management974948 +Node: Namespace Example975990 +Node: Namespace And Features978552 +Node: Namespace Summary979987 +Node: Arbitrary Precision Arithmetic981464 +Node: Computer Arithmetic982951 +Ref: table-numeric-ranges986717 +Ref: table-floating-point-ranges987211 +Ref: Computer Arithmetic-Footnote-1987870 +Node: Math Definitions987927 +Ref: table-ieee-formats990903 +Node: MPFR features991471 +Node: FP Math Caution993189 +Ref: FP Math Caution-Footnote-1994261 +Node: Inexactness of computations994630 +Node: Inexact representation995661 +Node: Comparing FP Values997021 +Node: Errors accumulate998262 +Node: Strange values999718 +Ref: Strange values-Footnote-11002306 +Node: Getting Accuracy1002411 +Node: Try To Round1005121 +Node: Setting precision1006020 +Ref: table-predefined-precision-strings1006717 +Node: Setting the rounding mode1008548 +Ref: table-gawk-rounding-modes1008922 +Ref: Setting the rounding mode-Footnote-11012854 +Node: Arbitrary Precision Integers1013033 +Ref: Arbitrary Precision Integers-Footnote-11016208 +Node: Checking for MPFR1016357 +Node: POSIX Floating Point Problems1017831 +Ref: POSIX Floating Point Problems-Footnote-11022116 +Node: Floating point summary1022154 +Node: Dynamic Extensions1024344 +Node: Extension Intro1025897 +Node: Plugin License1027163 +Node: Extension Mechanism Outline1027960 +Ref: figure-load-extension1028399 +Ref: figure-register-new-function1029965 +Ref: figure-call-new-function1031058 +Node: Extension API Description1033121 +Node: Extension API Functions Introduction1034834 +Ref: table-api-std-headers1036670 +Node: General Data Types1040920 +Ref: General Data Types-Footnote-11049626 +Node: Memory Allocation Functions1049925 +Ref: Memory Allocation Functions-Footnote-11054426 +Node: Constructor Functions1054525 +Node: API Ownership of MPFR and GMP Values1058178 +Node: Registration Functions1059491 +Node: Extension Functions1060191 +Node: Exit Callback Functions1065513 +Node: Extension Version String1066763 +Node: Input Parsers1067426 +Node: Output Wrappers1080147 +Node: Two-way processors1084659 +Node: Printing Messages1086924 +Ref: Printing Messages-Footnote-11088095 +Node: Updating ERRNO1088248 +Node: Requesting Values1088987 +Ref: table-value-types-returned1089724 +Node: Accessing Parameters1090833 +Node: Symbol Table Access1092070 +Node: Symbol table by name1092582 +Ref: Symbol table by name-Footnote-11095607 +Node: Symbol table by cookie1095735 +Ref: Symbol table by cookie-Footnote-11099920 +Node: Cached values1099984 +Ref: Cached values-Footnote-11103520 +Node: Array Manipulation1103673 +Ref: Array Manipulation-Footnote-11104764 +Node: Array Data Types1104801 +Ref: Array Data Types-Footnote-11107459 +Node: Array Functions1107551 +Node: Flattening Arrays1112049 +Node: Creating Arrays1119025 +Node: Redirection API1123792 +Node: Extension API Variables1126625 +Node: Extension Versioning1127336 +Ref: gawk-api-version1127765 +Node: Extension GMP/MPFR Versioning1129497 +Node: Extension API Informational Variables1131125 +Node: Extension API Boilerplate1132198 +Node: Changes from API V11136172 +Node: Finding Extensions1137744 +Node: Extension Example1138303 +Node: Internal File Description1139101 +Node: Internal File Ops1143181 +Ref: Internal File Ops-Footnote-11154531 +Node: Using Internal File Ops1154671 +Ref: Using Internal File Ops-Footnote-11157054 +Node: Extension Samples1157328 +Node: Extension Sample File Functions1158857 +Node: Extension Sample Fnmatch1166506 +Node: Extension Sample Fork1167993 +Node: Extension Sample Inplace1169211 +Node: Extension Sample Ord1172837 +Node: Extension Sample Readdir1173673 +Ref: table-readdir-file-types1174562 +Node: Extension Sample Revout1175630 +Node: Extension Sample Rev2way1176219 +Node: Extension Sample Read write array1176959 +Node: Extension Sample Readfile1178901 +Node: Extension Sample Time1179996 +Node: Extension Sample API Tests1181748 +Node: gawkextlib1182240 +Node: Extension summary1185158 +Node: Extension Exercises1188860 +Node: Language History1190102 +Node: V7/SVR3.11191758 +Node: SVR41193910 +Node: POSIX1195344 +Node: BTL1196725 +Node: POSIX/GNU1197454 +Node: Feature History1203232 +Node: Common Extensions1220407 +Node: Ranges and Locales1221690 +Ref: Ranges and Locales-Footnote-11226306 +Ref: Ranges and Locales-Footnote-21226333 +Ref: Ranges and Locales-Footnote-31226568 +Node: Contributors1226791 +Node: History summary1232788 +Node: Installation1234168 +Node: Gawk Distribution1235112 +Node: Getting1235596 +Node: Extracting1236559 +Node: Distribution contents1238197 +Node: Unix Installation1245258 +Node: Quick Installation1246062 +Node: Compiling with MPFR1248482 +Node: Shell Startup Files1249172 +Node: Additional Configuration Options1250261 +Node: Configuration Philosophy1252576 +Node: Compiling from Git1254972 +Node: Building the Documentation1255527 +Node: Non-Unix Installation1256911 +Node: PC Installation1257371 +Node: PC Binary Installation1258209 +Node: PC Compiling1259082 +Node: PC Using1260199 +Node: Cygwin1263752 +Node: MSYS1264976 +Node: VMS Installation1265578 +Node: VMS Compilation1266297 +Ref: VMS Compilation-Footnote-11267526 +Node: VMS Dynamic Extensions1267584 +Node: VMS Installation Details1269269 +Node: VMS Running1271531 +Node: VMS GNV1275810 +Node: Bugs1276524 +Node: Bug definition1277436 +Node: Bug address1280372 +Node: Usenet1283760 +Node: Performance bugs1284949 +Node: Asking for help1287870 +Node: Maintainers1289837 +Node: Other Versions1291031 +Node: Installation summary1299195 +Node: Notes1300559 +Node: Compatibility Mode1301353 +Node: Additions1302135 +Node: Accessing The Source1303060 +Node: Adding Code1304497 +Node: New Ports1310689 +Node: Derived Files1315064 +Ref: Derived Files-Footnote-11320724 +Ref: Derived Files-Footnote-21320759 +Ref: Derived Files-Footnote-31321357 +Node: Future Extensions1321471 +Node: Implementation Limitations1322129 +Node: Extension Design1323339 +Node: Old Extension Problems1324483 +Ref: Old Extension Problems-Footnote-11326001 +Node: Extension New Mechanism Goals1326058 +Ref: Extension New Mechanism Goals-Footnote-11329422 +Node: Extension Other Design Decisions1329611 +Node: Extension Future Growth1331724 +Node: Notes summary1332330 +Node: Basic Concepts1333488 +Node: Basic High Level1334169 +Ref: figure-general-flow1334451 +Ref: figure-process-flow1335137 +Ref: Basic High Level-Footnote-11338439 +Node: Basic Data Typing1338624 +Node: Glossary1341952 +Node: Copying1373839 +Node: GNU Free Documentation License1411382 +Node: Index1436502 End Tag Table |