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Diffstat (limited to 'doc/gawk.texi')
| -rw-r--r-- | doc/gawk.texi | 114 |
1 files changed, 55 insertions, 59 deletions
diff --git a/doc/gawk.texi b/doc/gawk.texi index 50496c26..736c42c3 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -4221,6 +4221,7 @@ in case some option becomes obsolete in a future version of @command{gawk}. @author Obi-Wan @end quotation +@cindex shells, sea This @value{SECTION} intentionally left blank. @@ -4233,7 +4234,7 @@ blank. @table @code @item -W nostalgia @itemx --nostalgia -Print the message @code{"awk: bailing out near line 1"} and dump core. +Print the message @samp{awk: bailing out near line 1} and dump core. This option was inspired by the common behavior of very early versions of Unix @command{awk} and by a t--shirt. The message is @emph{not} subject to translation in non-English locales. @@ -6558,7 +6559,7 @@ $ @kbd{echo a b | gawk 'BEGIN @{ FS = "" @}} @end example @cindex dark corner, @code{FS} as null string -@cindex FS variable, as null string +@cindex @code{FS} variable, as null string Traditionally, the behavior of @code{FS} equal to @code{""} was not defined. In this case, most versions of Unix @command{awk} simply treat the entire record as only having one field. @@ -26475,7 +26476,7 @@ and use translations from @command{awk}. @cindex portable object files @cindex files, portable object Once a program's translatable strings have been marked, they must -be extracted to create the initial @file{.po} file. +be extracted to create the initial @file{.pot} file. As part of translation, it is often helpful to rearrange the order in which arguments to @code{printf} are output. @@ -26570,7 +26571,7 @@ example, @samp{string} is the first argument and @samp{length(string)} is the se @example $ @kbd{gawk 'BEGIN @{} > @kbd{string = "Dont Panic"} -> @kbd{printf _"%2$d characters live in \"%1$s\"\n",} +> @kbd{printf "%2$d characters live in \"%1$s\"\n",} > @kbd{string, length(string)} > @kbd{@}'} @print{} 10 characters live in "Dont Panic" @@ -26604,7 +26605,7 @@ This is somewhat counterintuitive. and those with positional specifiers in the same string: @example -$ @kbd{gawk 'BEGIN @{ printf _"%d %3$s\n", 1, 2, "hi" @}'} +$ @kbd{gawk 'BEGIN @{ printf "%d %3$s\n", 1, 2, "hi" @}'} @error{} gawk: cmd. line:1: fatal: must use `count$' on all formats or none @end example @@ -27020,12 +27021,13 @@ as our example. @node Debugger Invocation @subsection How to Start the Debugger -Starting the debugger is almost exactly like running @command{awk}, except you have to -pass an additional option @option{--debug} or the corresponding short option @option{-D}. -The file(s) containing the program and any supporting code are given on the command -line as arguments to one or more @option{-f} options. (@command{gawk} is not designed -to debug command-line programs, only programs contained in files.) In our case, -we invoke the debugger like this: +Starting the debugger is almost exactly like running @command{gawk}, +except you have to pass an additional option @option{--debug} or the +corresponding short option @option{-D}. The file(s) containing the +program and any supporting code are given on the command line as arguments +to one or more @option{-f} options. (@command{gawk} is not designed +to debug command-line programs, only programs contained in files.) +In our case, we invoke the debugger like this: @example $ @kbd{gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile} @@ -27158,7 +27160,7 @@ gawk> @kbd{p NR} @noindent So we can see that @code{are_equal()} was only called for the second record -of the file. Of course, this is because our program contained a rule for +of the file. Of course, this is because our program contains a rule for @samp{NR == 1}: @example @@ -29325,7 +29327,7 @@ to begin with: gawk -M 'BEGIN @{ n = 13.0; print n % 2.0 @}' @end example -Note that for the particular example above, there is likely best +Note that for the particular example above, it is likely best to just use the following: @example @@ -29670,6 +29672,8 @@ the macros as if they were functions. @node General Data Types @subsection General Purpose Data Types +@cindex Robbins, Arnold +@cindex Ramey, Chet @quotation @i{I have a true love/hate relationship with unions.} @author Arnold Robbins @@ -29997,7 +30001,7 @@ Letter case in function names is significant. This is a pointer to the C function that provides the desired functionality. The function must fill in the result with either a number -or a string. @command{awk} takes ownership of any string memory. +or a string. @command{gawk} takes ownership of any string memory. As mentioned earlier, string memory @strong{must} come from @code{malloc()}. The @code{num_actual_args} argument tells the C function how many @@ -32067,7 +32071,7 @@ do_stat(int nargs, awk_value_t *result) awk_array_t array; int ret; struct stat sbuf; - /* default is stat() */ + /* default is lstat() */ int (*statfunc)(const char *path, struct stat *sbuf) = lstat; assert(result != NULL); @@ -32295,7 +32299,7 @@ upon success or less than zero upon error. In the latter case it updates @code{ERRNO}. @cindex @code{stat()} extension function -@item result = stat("/some/path", statdata [, follow]) +@item result = stat("/some/path", statdata @r{[}, follow@r{]}) The @code{stat()} function provides a hook into the @code{stat()} system call. It returns zero upon success or less than zero upon error. @@ -32505,19 +32509,23 @@ See @file{test/fts.awk} in the @command{gawk} distribution for an example. @node Extension Sample Fnmatch @subsection Interface To @code{fnmatch()} -@cindex @code{fnmatch()} extension function This extension provides an interface to the C library @code{fnmatch()} function. The usage is: -@example -@@load "fnmatch" +@table @code +@item @@load "fnmatch" +This is how you load the extension. -result = fnmatch(pattern, string, flags) -@end example +@cindex @code{fnmatch()} extension function +@item result = fnmatch(pattern, string, flags) +The return value is zero on success, @code{FNM_NOMATCH} +if the string did not match the pattern, or +a different non-zero value if an error occurred. +@end table -The @code{fnmatch} extension adds a single function named -@code{fnmatch()}, one constant (@code{FNM_NOMATCH}), and an array of -flag values named @code{FNM}. +Besides the @code{fnmatch()} function, the @code{fnmatch} extension +adds one constant (@code{FNM_NOMATCH}), and an array of flag values +named @code{FNM}. The arguments to @code{fnmatch()} are: @@ -32533,10 +32541,6 @@ Either zero, or the bitwise OR of one or more of the flags in the @code{FNM} array. @end table -The return value is zero on success, @code{FNM_NOMATCH} -if the string did not match the pattern, or -a different non-zero value if an error occurred. - The flags are follows: @multitable @columnfractions .25 .75 @@ -32580,15 +32584,15 @@ This is how you load the extension. @cindex @code{fork()} extension function @item pid = fork() -This function creates a new process. The return value is the zero in the -child and the process-id number of the child in the parent, or @minus{}1 +This function creates a new process. The return value is zero in the +child and the process-ID number of the child in the parent, or @minus{}1 upon error. In the latter case, @code{ERRNO} indicates the problem. In the child, @code{PROCINFO["pid"]} and @code{PROCINFO["ppid"]} are updated to reflect the correct values. @cindex @code{waitpid()} extension function @item ret = waitpid(pid) -This function takes a numeric argument, which is the process-id to +This function takes a numeric argument, which is the process-ID to wait for. The return value is that of the @code{waitpid()} system call. @@ -34212,7 +34216,7 @@ The @option{-i} and @option{--include} options load @command{awk} library files. @item -The @option{-l} and @option{--load} options for load compiled dynamic extensions. +The @option{-l} and @option{--load} options load compiled dynamic extensions. @item The @option{-M} and @option{--bignum} options enable MPFR. @@ -34233,7 +34237,7 @@ Support for high precision arithmetic with MPFR. @item The @code{and()}, @code{or()} and @code{xor()} functions -allow any number of arguments, +changed to allow any number of arguments, with a minimum of two (@pxref{Bitwise Functions}). @@ -34258,18 +34262,18 @@ the three most widely-used freely available versions of @command{awk} @multitable {@file{/dev/stderr} special file} {BWK Awk} {Mawk} {GNU Awk} @headitem Feature @tab BWK Awk @tab Mawk @tab GNU Awk @item @samp{\x} Escape sequence @tab X @tab X @tab X -@item @code{RS} as regexp @tab @tab X @tab X @item @code{FS} as null string @tab X @tab X @tab X @item @file{/dev/stdin} special file @tab X @tab X @tab X @item @file{/dev/stdout} special file @tab X @tab X @tab X @item @file{/dev/stderr} special file @tab X @tab X @tab X -@item @code{**} and @code{**=} operators @tab X @tab @tab X -@item @code{fflush()} function @tab X @tab X @tab X -@item @code{func} keyword @tab X @tab @tab X -@item @code{nextfile} statement @tab X @tab X @tab X @item @code{delete} without subscript @tab X @tab X @tab X +@item @code{fflush()} function @tab X @tab X @tab X @item @code{length()} of an array @tab X @tab X @tab X +@item @code{nextfile} statement @tab X @tab X @tab X +@item @code{**} and @code{**=} operators @tab X @tab @tab X +@item @code{func} keyword @tab X @tab @tab X @item @code{BINMODE} variable @tab @tab X @tab X +@item @code{RS} as regexp @tab @tab X @tab X @item Time related functions @tab @tab X @tab X @end multitable @@ -34358,10 +34362,10 @@ the @command{gawk} maintainer grew weary of trying to explain that was in the user's locale. During the development of version 4.0, he modified @command{gawk} to always treat ranges in the original, pre-POSIX fashion, unless @option{--posix} was used (@pxref{Options}).@footnote{And -thus was born the Campain for Rational Range Interpretation (or RRI). A number -of GNU tools, such as @command{grep} and @command{sed}, have either -implemented this change, or will soon. Thanks to Karl Berry for coining the phrase -``Rational Range Interpretation.''} +thus was born the Campaign for Rational Range Interpretation (or +RRI). A number of GNU tools have either implemented this change, +or will soon. Thanks to Karl Berry for coining the phrase ``Rational +Range Interpretation.''} Fortunately, shortly before the final release of @command{gawk} 4.0, the maintainer learned that the 2008 standard had changed the @@ -34374,7 +34378,7 @@ and By using this lovely technical term, the standard gives license to implementors to implement ranges in whatever way they choose. The @command{gawk} maintainer chose to apply the pre-POSIX meaning in all -cases: the default regexp matching; with @option{--traditional}, and with +cases: the default regexp matching; with @option{--traditional} and with @option{--posix}; in all cases, @command{gawk} remains POSIX compliant. @node Contributors @@ -35015,7 +35019,7 @@ please send in a bug report (@pxref{Bugs}). Of course, once you've built @command{gawk}, it is likely that you will wish to install it. To do so, you need to run the command @samp{make -check}, as a user with the appropriate permissions. How to do this +install}, as a user with the appropriate permissions. How to do this varies by system, but on many systems you can use the @command{sudo} command to do so. The command then becomes @samp{sudo make install}. It is likely that you will be asked for your password, and you will have @@ -35341,11 +35345,10 @@ multibyte functionality is not available. @c STARTOFRANGE pcgawon @cindex PC operating systems, @command{gawk} on -With the exception of the Cygwin environment, -the @samp{|&} operator and TCP/IP networking -(@pxref{TCP/IP Networking}) -are not supported for MS-DOS or MS-Windows. EMX (OS/2 only) does support -at least the @samp{|&} operator. +Under MS-DOS and MS-Windows, the Cygwin and MinGW environments support +both the @samp{|&} operator and TCP/IP networking +(@pxref{TCP/IP Networking}). +EMX (OS/2 only) supports at least the @samp{|&} operator. @cindex search paths @cindex search paths, for source files @@ -35475,7 +35478,7 @@ moved into the @code{BEGIN} rule. @command{gawk} can be built and used ``out of the box'' under MS-Windows if you are using the @uref{http://www.cygwin.com, Cygwin environment}. -This environment provides an excellent simulation of Unix, using the +This environment provides an excellent simulation of GNU/Linux, using the GNU tools, such as Bash, the GNU Compiler Collection (GCC), GNU Make, and other GNU programs. Compilation and installation for Cygwin is the same as for a Unix system: @@ -35491,13 +35494,6 @@ When compared to GNU/Linux on the same system, the @samp{configure} step on Cygwin takes considerably longer. However, it does finish, and then the @samp{make} proceeds as usual. -@quotation NOTE -The @samp{|&} operator and TCP/IP networking -(@pxref{TCP/IP Networking}) -are fully supported in the Cygwin environment. This is not true -for any other environment on MS-Windows. -@end quotation - @node MSYS @appendixsubsubsec Using @command{gawk} In The MSYS Environment @@ -35676,7 +35672,7 @@ add the @command{gawk} and @command{awk} to the system wide @samp{DCLTABLES}. The DCL syntax is documented in the @file{gawk.hlp} file. -Optionally, @file{gawk.hlp} entry can be loaded into a VMS help library: +Optionally, the @file{gawk.hlp} entry can be loaded into a VMS help library: @example $ @kbd{LIBRARY/HELP sys$help:helplib [.vms]gawk.hlp} @@ -36018,7 +36014,7 @@ from GCC (the GNU Compiler Collection) works quite nicely. for a list of extensions in this @command{awk} that are not in POSIX @command{awk}. @cindex Brennan, Michael -@cindex @command{mawk} program +@cindex @command{mawk} utility @cindex source code, @command{mawk} @item @command{mawk} Michael Brennan wrote an independent implementation of @command{awk}, |