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diff --git a/doc/gawk.texi b/doc/gawk.texi index 42560264..542577e0 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -3,6 +3,9 @@ TODO: Globally add () after built in and awk function names. Go through CAUTION, NOTE, @strong, @quotation, etc. + Document common extensions with COMMONEXT marking & index entry. + Pick a reasonable name for BWK awk and use it everywhere (search + for Bell Laboratories) DONE: @end ignore @c %**start of header (This is for running Texinfo on a region.) @@ -72,6 +75,15 @@ DONE: @set DARKCORNER (d.c.) @set COMMONEXT (c.e.) @end ifdocbook +@ifplaintext +@set DOCUMENT book +@set CHAPTER chapter +@set APPENDIX appendix +@set SECTION section +@set SUBSECTION subsection +@set DARKCORNER (d.c.) +@set COMMONEXT (c.e.) +@end ifplaintext @c some special symbols @iftex @@ -528,13 +540,16 @@ particular records in a file and perform operations upon them. * Command Line:: How to run @command{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 @command{gawk} uses. * AWKPATH Variable:: Searching directories for @command{awk} programs. +* Other Environment Variables:: The environment variables. * Exit Status:: @command{gawk}'s exit status. * Include Files:: Including other files into your program. * Obsolete:: Obsolete Options and/or features. * Undocumented:: Undocumented Options and Features. -* Known Bugs:: Known Bugs in @command{gawk}. * Library Names:: How to best name private global variables in library functions. * General Functions:: Functions that are of general use. @@ -11062,11 +11077,13 @@ for an example that does this. @cindex dark corner, @code{exit} statement If an argument is supplied to @code{exit}, its value is used as the exit status code for the @command{awk} process. If no argument is supplied, -@code{exit} returns status zero (success). In the case where an argument +@code{exit} causes @command{awk} to return a ``success'' status. +In the case where an argument is supplied to a first @code{exit} statement, and then @code{exit} is called a second time from an @code{END} rule with no argument, @command{awk} uses the previously supplied exit value. @value{DARKCORNER} +@xref{Exit Status}, for more information. @cindex programming conventions, @code{exit} statement For example, suppose an error condition occurs that is difficult or @@ -17530,8 +17547,6 @@ When called this way, @command{gawk} ``pretty prints'' the program into @c ENDOFRANGE awkp @c ENDOFRANGE proawk - - @node Invoking Gawk @chapter Running @command{awk} and @command{gawk} @@ -17541,24 +17556,21 @@ and @command{gawk}-specific command-line options, and what @command{gawk} do with non-option arguments. It then proceeds to cover how @command{gawk} searches for source files, obsolete options and/or features, and known bugs in @command{gawk}. -This @value{CHAPTER} rounds out the discussion of @command{awk} -as a program and as a language. -While a number of the options and features described here were -discussed in passing earlier in the book, this @value{CHAPTER} provides the -full details. +Many of the options and features described here are discussed in +more detail later in the @value{DOCUMENT}; feel free to skip over +things in this @value{CHAPTER} that don't interest you right now. @menu * Command Line:: How to run @command{awk}. * Options:: Command-line options and their meanings. * Other Arguments:: Input file names and variable assignments. -* AWKPATH Variable:: Searching directories for @command{awk} - programs. +* Naming Standard Input:: How to specify standard input with other files. +* Environment Variables:: The environment variables @command{gawk} uses. * Exit Status:: @command{gawk}'s exit status. * Include Files:: Including other files into your program. * Obsolete:: Obsolete Options and/or features. * Undocumented:: Undocumented Options and Features. -* Known Bugs:: Known Bugs in @command{gawk}. @end menu @node Command Line @@ -17626,7 +17638,7 @@ Each long option for @command{gawk} has a corresponding POSIX-style option. The long and short options are interchangeable in all contexts. -The options and their meanings are as follows: +The following list describes options mandated by the POSIX standard: @table @code @item -F @var{fs} @@ -17634,7 +17646,7 @@ The options and their meanings are as follows: @cindex @code{-F} option @cindex @code{--field-separator} option @cindex @code{FS} variable, @code{--field-separator} option and -Sets the @code{FS} variable to @var{fs} +Set the @code{FS} variable to @var{fs} (@pxref{Field Separators}). @item -f @var{source-file} @@ -17642,15 +17654,18 @@ Sets the @code{FS} variable to @var{fs} @cindex @code{-f} option @cindex @code{--file} option @cindex @command{awk} programs, location of -Indicates that the @command{awk} program is to be found in @var{source-file} +Read @command{awk} program source from @var{source-file} instead of in the first non-option argument. +This option may be given multiple times; the @command{awk} +program consists of the concatenation the contents of +each specified @var{source-file}. @item -v @var{var}=@var{val} @itemx --assign @var{var}=@var{val} @cindex @code{-v} option @cindex @code{--assign} option @cindex variables, setting -Sets the variable @var{var} to the value @var{val} @emph{before} +Set the variable @var{var} to the value @var{val} @emph{before} execution of the program begins. Such variable values are available inside the @code{BEGIN} rule (@pxref{Other Arguments}). @@ -17671,7 +17686,7 @@ predefined value you may have given. @itemx -mr @var{N} @cindex @code{-mf}/@code{-mr} options @cindex memory, setting limits -Sets various memory limits to the value @var{N}. The @samp{f} flag sets +Set various memory limits to the value @var{N}. The @samp{f} flag sets the maximum number of fields and the @samp{r} flag sets the maximum record size. These two flags and the @option{-m} option are from the Bell Laboratories research version of Unix @command{awk}. They are provided @@ -17683,8 +17698,9 @@ it continues to accept them to avoid breaking old programs.) @item -W @var{gawk-opt} @cindex @code{-W} option -Following the POSIX standard, implementation-specific -options are supplied as arguments to the @option{-W} option. These options +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. @@ -17693,7 +17709,7 @@ The full list of @command{gawk}-specific options is provided next. @item -- @cindex command line, options, end of @cindex options, command-line, end of -Signals the end of the command-line options. The following arguments +Signal the end of the command-line options. The following arguments are not treated as options even if they begin with @samp{-}. This interpretation of @option{--} follows the POSIX argument parsing conventions. @@ -17703,11 +17719,12 @@ conventions. This is useful if you have @value{FN}s that start with @samp{-}, or in shell scripts, if you have @value{FN}s that will be specified by the user that could start with @samp{-}. +It is also useful for passing options on to the @command{awk} +program; see @ref{Getopt Function}. @end table @c ENDOFRANGE gnulo @c ENDOFRANGE longo -The previous list described options mandated by the POSIX standard. The following list describes @command{gawk}-specific options: @table @code @@ -17715,12 +17732,12 @@ The following list describes @command{gawk}-specific options: @itemx --characters-as-bytes @cindex @code{-b} option @cindex @code{--characters-as-bytes} option -Causes @command{gawk} to treat all input data as single-byte characters. +Cause @command{gawk} to treat all input data as single-byte characters. Normally, @command{gawk} follows the POSIX standard and attempts to process its input data according to the current locale. This can often involve -converting multi-byte characters into wide characters (internally), and +converting multibyte characters into wide characters (internally), and can lead to problems or confusion if the input data does not contain valid -multi-byte characters. This option is an easy way to tell @command{gawk}: +multibyte characters. This option is an easy way to tell @command{gawk}: ``hands off my data!''. @item -c @@ -17728,10 +17745,9 @@ multi-byte characters. This option is an easy way to tell @command{gawk}: @cindex @code{--c} option @cindex @code{--traditional} option @cindex compatibility mode (@command{gawk}), specifying -Specifies @dfn{compatibility mode}, in which the GNU extensions to +Specify @dfn{compatibility mode}, in which the GNU extensions to the @command{awk} language are disabled, so that @command{gawk} behaves just like the Bell Laboratories research version of Unix @command{awk}. -@option{--traditional} is the preferred form of this option. @xref{POSIX/GNU}, which summarizes the extensions. Also see @ref{Compatibility Mode}. @@ -17750,8 +17766,8 @@ Print the short version of the General Public License and then exit. @cindex @code{awkvars.out} file @cindex files, @code{awkvars.out} @cindex variables, global, printing list of -Prints a sorted list of global variables, their types, and final values -to @var{file}. If no @var{file} is provided, @command{gawk} prints this +Print a sorted list of global variables, their types, and final values +to @var{file}. If no @var{file} is provided, print this list to the file named @file{awkvars.out} in the current directory. @cindex troubleshooting, typographical errors@comma{} global variables @@ -17768,9 +17784,9 @@ names like @code{i}, @code{j}, etc.) @cindex @code{-e} option @cindex @code{--source} option @cindex source code, mixing -Allows you to mix source code in files with source +Provide program source code in the @var{program-text}. +This option allows you to mix source code in files with source code that you enter on the command line. -Program source code is taken from the @var{program-text}. This is particularly useful when you have library functions that you want to use from your command-line programs (@pxref{AWKPATH Variable}). @@ -17781,16 +17797,23 @@ programs (@pxref{AWKPATH Variable}). @cindex @code{--exec} option @cindex @command{awk} programs, location of @cindex CGI, @command{awk} scripts for -Similar to @option{-f}, reads @command{awk} program text from @var{file}. -There are two differences. The first is that this option also terminates option processing; anything +Similar to @option{-f}, read @command{awk} program text from @var{file}. +There are two differences from @option{-f}: + +@itemize @bullet +@item +This option terminates option processing; anything else on the command line is passed on directly to the @command{awk} program. -The second is that command line variable assignments of the form + +@item +Command-line variable assignments of the form @samp{@var{var}=@var{value}} are disallowed. +@end itemize 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 @command{awk} source code (via -@option{--source}) to the CGI application. This option should be used +(or other) user from passing in options, assignments, or @command{awk} source +code (via @option{--source}) to the CGI application. This option should be used with @samp{#!} scripts (@pxref{Executable Scripts}), like so: @example @@ -17805,8 +17828,8 @@ with @samp{#!} scripts (@pxref{Executable Scripts}), like so: @cindex @code{--gen-pot} option @cindex portable object files, generating @cindex files, portable object, generating -Analyzes the source program and -generates a GNU @code{gettext} Portable Object file on standard +Analyze the source program and +generate a GNU @code{gettext} Portable Object Template file on standard output for all string constants that have been marked for translation. @xref{Internationalization}, for information about this option. @@ -17818,7 +17841,7 @@ for information about this option. @cindex GNU long options, printing list of @cindex options, printing list of @cindex printing, list of options -Prints a ``usage'' message summarizing the short and long style options +Print a ``usage'' message summarizing the short and long style options that @command{gawk} accepts and then exit. @item -L @r{[}value@r{]} @@ -17827,7 +17850,7 @@ that @command{gawk} accepts and then exit. @cindex @code{--lint} option @cindex lint checking, issuing warnings @cindex warnings, issuing -Warns about constructs that are dubious or nonportable to +Warn about constructs that are dubious or nonportable to other @command{awk} implementations. Some warnings are issued when @command{gawk} first reads your program. Others are issued at runtime, as your program executes. @@ -17862,14 +17885,14 @@ Use with care. @itemx --use-lc-numeric @cindex @code{-N} option @cindex @code{--use-lc-numeric} option -This option forces the use of the locale's decimal point character +Force the use of the locale's decimal point character when parsing numeric input data (@pxref{Locales}). @item -O @itemx --optimize @cindex @code{--optimize} option @cindex @code{-O} option -Enables some optimizations on the internal representation of the program. +Enable some optimizations on the internal representation of the program. At the moment this includes just simple constant folding. The @command{gawk} maintainer hopes to add more optimizations over time. @@ -17895,7 +17918,7 @@ call counts for each function. @cindex @code{--posix} option @cindex POSIX mode @cindex @command{gawk}, extensions@comma{} disabling -Operates in strict POSIX mode. This disables all @command{gawk} +Operate in strict POSIX mode. This disables all @command{gawk} extensions (just like @option{--traditional}) and adds the following additional restrictions: @@ -17966,11 +17989,11 @@ also issues a warning if both options are supplied. @cindex @code{-r} option @cindex @code{--re-interval} option @cindex regular expressions, interval expressions and -Allows interval expressions +Allow interval expressions (@pxref{Regexp Operators}) in regexps. -This is now the default behavior for @command{gawk}. -Nevertheless, this option remains for both backward compatibility, +This is now @command{gawk}'s default behavior. +Nevertheless, this option remains both for backward compatibility, and for use in combination with the @option{--traditional} option. @item -S @@ -17978,19 +18001,19 @@ and for use in combination with the @option{--traditional} option. @cindex @code{-S} option @cindex @code{--sandbox} option @cindex sandbox mode -In sandbox mode, the @code{system()} function, +Disable the @code{system()} function, input redirections with @code{getline}, -output redirections with @code{print} and @code{printf} -and dynamic extensions are disabled. +output redirections with @code{print} and @code{printf}, +and dynamic extensions. This is particularly useful when you want to run @command{awk} scripts from questionable sources and need to make sure the scripts -can't access your system (other then the specified input data file). +can't access your system (other than the specified input data file). @item -t @itemx --lint-old @cindex @code{--L} option @cindex @code{--lint-old} option -Warns about constructs that are not available in the original version of +Warn about constructs that are not available in the original version of @command{awk} from Version 7 Unix (@pxref{V7/SVR3.1}). @@ -17999,7 +18022,7 @@ Warns about constructs that are not available in the original version of @cindex @code{-V} option @cindex @code{--version} option @cindex @command{gawk}, versions of, information about@comma{} printing -Prints version information for this particular copy of @command{gawk}. +Print version information for this particular copy of @command{gawk}. This allows you to determine if your copy of @command{gawk} is up to date with respect to whatever the Free Software Foundation is currently distributing. @@ -18029,7 +18052,8 @@ of having to be included into each individual program. @ref{Definition Syntax}, function names must be unique.) -Library functions can still be used, even if the program is entered at the terminal, +With standard @command{awk}, library functions can still be used, even +if the program is entered at the terminal, by specifying @samp{-f /dev/tty}. After typing your program, type @kbd{@value{CTL}-d} (the end-of-file character) to terminate it. (You may also use @samp{-f -} to read program source from the standard @@ -18094,7 +18118,7 @@ input files to be processed in the order specified. However, an argument that has the form @code{@var{var}=@var{value}}, assigns the value @var{value} to the variable @var{var}---it does not specify a file at all. -(This was discussed earlier in +(See also @ref{Assignment Options}.) @cindex @code{ARGIND} variable, command-line arguments @@ -18152,8 +18176,47 @@ Given the variable assignment feature, the @option{-F} option for setting the value of @code{FS} is not strictly necessary. It remains for historical compatibility. +@node Naming Standard Input +@section Naming Standard Input + +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 @command{awk}, +is to use a single, standalone minus sign or dash, @samp{-}. For example: + +@example +@var{some_command} | awk -f myprog.awk file1 - file2 +@end example + +@noindent +Here, @command{awk} first reads @file{file1}, then it reads +the output of @var{some_command}, and finally it reads +@file{file2}. + +You may also use @code{"-"} to name standard input when reading +files with @code{getline} (@pxref{Getline/File}). + +In addition, @command{gawk} allows you to specify the special +@value{FN} @file{/dev/stdin}, both on the command line and +with @code{getline}. +Some other versions of @command{awk} also support this, but it +is not standard. + +@node Environment Variables +@section The Environment Variables @command{gawk} Uses + +A number of environment variables influence how @command{gawk} +behaves. + +@menu +* AWKPATH Variable:: Searching directories for @command{awk} programs. +* Other Environment Variables:: The environment variables. +@end menu + @node AWKPATH Variable -@section The @env{AWKPATH} Environment Variable +@subsection The @env{AWKPATH} Environment Variable @cindex @env{AWKPATH} environment variable @cindex directories, searching @cindex search paths, for source files @@ -18197,18 +18260,23 @@ This is true for both @option{--traditional} and @option{--posix}. @xref{Options}. @quotation NOTE -If you want files in the current directory to be found, -you must include the current directory in the path, either by including -@file{.} explicitly in the path or by writing a null entry in the +To include +the current directory in the path, either place +@file{.} 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 (@samp{::}).) If the -current directory is not included in the path, then files cannot be -found in the current directory. This path search mechanism is identical +colon or by placing two colons next to each other (@samp{::}).) +This path search mechanism is similar to the shell's. @c someday, @cite{The Bourne Again Shell}.... + +However, @command{gawk} always looks in the current directory before +before searching @env{AWKPATH}, so there is no real reason to include +the current directory in the search path. +@c Prior to 4.0, gawk searched the current directory after the +@c path search, but it's not worth documenting it. @end quotation -Starting with @value{PVERSION} 3.0, if @env{AWKPATH} is not defined in the +If @env{AWKPATH} is not defined in the environment, @command{gawk} places its default search path into @code{ENVIRON["AWKPATH"]}. This makes it easy to determine the actual search path that @command{gawk} will use @@ -18220,6 +18288,68 @@ sense: the @env{AWKPATH} environment variable is used to find the program source files. Once your program is running, all the files have been found, and @command{gawk} no longer needs to use @env{AWKPATH}. +@node Other Environment Variables +@subsection Other Environment Variables + +A number of other environment variables affect @command{gawk}'s +behavior, but they are more specialized. Those in the following +list are meant to be used by regular users. + +@table @env +@item POSIXLY_CORRECT +If this variable exists, @command{gawk} switches to POSIX compatibility +mode, disabling all traditional and GNU extensions. +@xref{Options}. + +@item GAWK_SOCK_RETRIES +Controls the number of time @command{gawk} will attempt to +retry a two-way TCP/IP (socket) connection before giving up. +@xref{TCP/IP Networking}. + +@item GAWK_MSEC_SLEEP +Specifies the interval between connection retries, +in milliseconds. On systems that do not support +the @code{usleep()} system call, +the value is rounded up to an integral number of seconds. +@end table + +The environment variables in the following table are meant +for use by the @command{gawk} developers for testing and tuning. +They are subject to change. The variables are: + +@table @env +@item AVG_CHAIN_MAX +The average number of items @command{gawk} will maintain on a +hash chain for managing arrays. + +@item AWK_HASH +If this variable exists with a value of @samp{gst}, @command{gawk} +will switch to using the hash function from GNU Smalltalk for +managing arrays. +This function may be marginally faster than the standard function. + +@item AWKREADFUNC +If this variable exists, @command{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. + +@item GAWK_NO_DFA +If this variable exists, @command{gawk} does not use the DFA regexp matcher +for ``does it match'' kinds of tests. This can cause @command{gawk} +to be slower. Its purpose is to help isolate differences between the +two regexp matchers that @command{gawk} uses internally. (There aren't +supposed to be differences, but occasionally theory and practice don't match up.) + +@item GAWK_STACKSIZE +This specifies the amount by which @command{gawk} should grow its +internal evaluation stack, when needed. + +@item TIDYMEM +If this variable exists, @command{gawk} uses the @code{mtrace()} library +calls from GNU LIBC to help track down possible memory leaks. +@end table + @node Exit Status @section @command{gawk}'s Exit Status @@ -18247,20 +18377,18 @@ to @code{EXIT_FAILURE}. @strong{FIXME:} This section still needs some editing. -Beginning with version @strong{FIXME:} 3.1.8-bc of @command{gawk}, the -@samp{@@include} keyword can be used to read external source @command{awk} -files. That gives the ability to split huge @command{awk} source files -into smaller and manageable files and also to reuse common @command{awk} +The @samp{@@include} keyword can be used to read external source @command{awk} +files. That gives the ability to split large @command{awk} source files +into smaller, more manageable pieces, and also lets you reuse common @command{awk} code from various @command{awk} scripts. In other words, you can group -together @command{awk} functions, used to carry out some sort of tasks, +together @command{awk} functions, used to carry out specific tasks, in external files. These files can be used just like function libraries, using the @samp{@@include} keyword in conjuction with the @code{AWKPATH} environment variable. Let's see an example to demonstrate file inclusion in @command{gawk}. -To do so, we'll use two (trivial) @command{awk} scripts, namely the -@file{test1} and @file{test2} @command{gawk} scripts. Here follows the -@file{test1} @command{gawk} script file: +To do so, we'll use two (trivial) @command{awk} scripts, namely +@file{test1} and @file{test2}. Here is the @file{test1} script: @example BEGIN @{ @@ -18269,7 +18397,7 @@ BEGIN @{ @end example @noindent -and the @file{test2} file: +and here is @file{test2}: @example @@include "test1" @@ -18278,8 +18406,8 @@ BEGIN @{ @} @end example -Running @command{gawk} with the @file{test2} -script you'll get the following result: +Running @command{gawk} with @file{test2} +produces the following result: @example $ @kbd{gawk -f test2} @@ -18290,8 +18418,8 @@ $ @kbd{gawk -f test2} @code{gawk} runs the @file{test2} script where @file{test1} has been included in the source of @file{test2} by means of the @samp{@@include} keyword. So, to include external @command{awk} source files you just -use @samp{@@include} followed by the name of the file to be included in -double quotes. +use @samp{@@include} followed by the name of the file to be included, +enclosed in double quotes. @quotation NOTE Keep in mind that this is a language construct and the @value{FN} cannot @@ -18334,29 +18462,28 @@ or @noindent are valid. The @code{AWKPATH} environment variable can be of great -value in @samp{@@include} constructs. The same rules dominating the use -of @code{AWKPATH} variable in command line file searches are valid in -@samp{@@include} constructs too. That can be prooved very helpful in +value when using @samp{@@include}. The same rules for the use +of the @code{AWKPATH} variable in command line file searches apply to +@samp{@@include} also. This is very helpful in constructing @command{gawk} function libraries. You can edit huge -scripts containing usefull @command{gawk} libraries and put those +scripts containing useful @command{gawk} libraries 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 accordingly -the @code{AWKPATH} environment variable and then use @samp{@@include} +using either the full pathnames of the files or by setting +the @code{AWKPATH} environment variable accordingly and then using @samp{@@include} with just the name part of the full file pathname. Of course you can have more than one directory to keep library files; the more complex -the working enviroment is, the more directories you need to organize +the working enviroment is, the more directories you may need to organize the files to be included. -The whole stuff of file inclusion can, of course, be carried out in the -command line, using as many @option{-f} options as required with the -files to be included as arguments, but the @samp{@@include} keyword +Given the ability to specify multiple @option{-f} options, the +@samp{@@include} mechanism is not strictly necessary. +However, the @samp{@@include} keyword can help you in constructing self-contained @command{gawk} programs, thus reducing the need of writing complex and tedious command lines. -@code{AWKPATH} is also used by the @samp{@@include} mechanism, that is -the files to be included will be seeked in the directories specified. -Keep in mind, however, that the current directory is been searched first, -either it's listed in the @code{AWKPATH} string or not. +As mentioned in @ref{AWKPATH Variable}, the current directory is always +search first for source files, before searching in @env{AWKPATH}, +and this also applies to files named with @samp{@@include}. @node Obsolete @section Obsolete Options and/or Features @@ -18372,27 +18499,11 @@ they will @emph{not} be in the next release). @c update this section for each release! -@ignore -@cindex @code{next file} statement, deprecated -@cindex @code{nextfile} statement, @code{next file} statement and -@end ignore -For @value{PVERSION} @value{VERSION} of @command{gawk}, there are no -deprecated command-line options -@c or other deprecated features -from the previous version of @command{gawk}. -@ignore -The use of @samp{next file} (two words) for @code{nextfile} was deprecated -in @command{gawk} 3.0 but still worked. Starting with @value{PVERSION} 3.1, the -two-word usage is no longer accepted. -@end ignore - -The process-related special files -@file{/dev/pid}, @file{/dev/ppid}, @file{/dev/pgrpid}, and -@file{/dev/user} were deprecated in @command{gawk} 3.1, but still -worked. As of @value{PVERSION} 3.2, they are no longer interpreted specially -by @command{gawk}. -(Use @code{PROCINFO} instead; see -@ref{Auto-set}.) +The process-related special files @file{/dev/pid}, @file{/dev/ppid}, +@file{/dev/pgrpid}, and @file{/dev/user} were deprecated in @command{gawk} +3.1, but still worked. As of @value{PVERSION} 4.0, they are no longer +interpreted specially by @command{gawk}. (Use @code{PROCINFO} instead; +see @ref{Auto-set}.) @ignore This @value{SECTION} @@ -18467,43 +18578,8 @@ Similarly, you may use @code{print} or @code{printf} statements in the @var{init} and @var{increment} parts of a @code{for} loop. This is another long-undocumented ``feature'' of Unix @code{awk}. -If the environment variable @env{WHINY_USERS} exists -when @command{gawk} is run, -then the associative @code{for} loop will go through the array -indices in sorted order. -The comparison used for sorting is simple string comparison; -any non-English or non-ASCII locales are not taken into account. -@code{IGNORECASE} does not affect the comparison either. - -In addition, if @env{WHINY_USERS} is set, the profiled version of a -program generated by @option{--profile} will print all 8-bit characters -verbatim, instead of using the octal equivalent. - @end ignore -@node Known Bugs -@section Known Bugs in @command{gawk} -@cindex @command{gawk}, debugging -@cindex debugging @command{gawk} -@cindex troubleshooting, @command{gawk} - -@itemize @bullet -@cindex troubleshooting, @code{-F} option -@cindex @code{-F} option, troubleshooting -@cindex @code{FS} variable, changing value of -@item -The @option{-F} option for changing the value of @code{FS} -(@pxref{Options}) -is not necessary given the command-line variable -assignment feature; it remains only for backward compatibility. - -@item -Syntactically invalid single-character programs tend to overflow -the parse stack, generating a rather unhelpful message. Such programs -are surprisingly difficult to diagnose in the completely general case, -and the effort to do so really is not worth it. -@end itemize - @ignore @c Try this @iftex |