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Diffstat (limited to 'doc/gawktexi.in')
| -rw-r--r-- | doc/gawktexi.in | 90 |
1 files changed, 68 insertions, 22 deletions
diff --git a/doc/gawktexi.in b/doc/gawktexi.in index 2269077e..bb94aa1f 100644 --- a/doc/gawktexi.in +++ b/doc/gawktexi.in @@ -46,7 +46,7 @@ @c applies to and all the info about who's publishing this edition @c These apply across the board. -@set UPDATE-MONTH June, 2014 +@set UPDATE-MONTH July, 2014 @set VERSION 4.1 @set PATCHLEVEL 1 @@ -3796,10 +3796,8 @@ No space is allowed between the @option{-o} and @var{file}, if @var{file} is supplied. @quotation NOTE -Due to the way @command{gawk} has evolved, with this option -your program is still executed. This will change in the -next major release such that @command{gawk} will only -pretty-print the program and not run it. +In the past, this option would also execute your program. +This is no longer the case. @end quotation @item @option{-O} @@ -4285,11 +4283,6 @@ two regexp matchers that @command{gawk} uses internally. (There aren't supposed to be differences, but occasionally theory and practice don't coordinate with each other.) -@item GAWK_NO_PP_RUN -If this variable exists, then when invoked with the @option{--pretty-print} -option, @command{gawk} skips running the program. This variable will -not survive into the next major release. - @item GAWK_STACKSIZE This specifies the amount by which @command{gawk} should grow its internal evaluation stack, when needed. @@ -13887,10 +13880,18 @@ next file is opened. An associative array containing the values of the environment. The array indices are the environment variable names; the elements are the values of the particular environment variables. For example, -@code{ENVIRON["HOME"]} might be @code{"/home/arnold"}. Changing this array -does not affect the environment passed on to any programs that -@command{awk} may spawn via redirection or the @code{system()} function. -(In a future version of @command{gawk}, it may do so.) +@code{ENVIRON["HOME"]} might be @code{/home/arnold}. + +For POSIX @command{awk}, changing this array does not affect the +environment passed on to any programs that @command{awk} may spawn via +redirection or the @code{system()} function. + +However, beginning with version 4.2, if not in POSIX +compatibility mode, @command{gawk} does update its own environment when +@code{ENVIRON} is changed, thus changing the environment seen by programs +that it creates. You should therefore be especially careful if you +modify @code{ENVIRON["PATH"]"}, which is the search path for finding +executable programs. Some operating systems may not have environment variables. On such systems, the @code{ENVIRON} array is empty (except for @@ -15930,6 +15931,23 @@ You can use @samp{pi = atan2(0, -1)} to retrieve the value of @cindex cosine Return the cosine of @var{x}, with @var{x} in radians. +@item @code{div(@var{numerator}, @var{denominator}, @var{result})} +@cindexawkfunc{div} +@cindex div +Perform integer division, similar to the standard C function of the +same name. First, truncate @code{numerator} and @code{denominator} +towards zero, creating integer values. Clear the @code{result} +array, and then set @code{result["quotient"]} to the result of +@samp{numerator / denominator}, truncated towards zero to an integer, +and set @code{result["remainder"]} to the result of @samp{numerator % +denominator}, truncated towards zero to an integer. This function is +primarily intended for use with arbitrary length integers; it avoids +creating MPFR arbitrary precision floating-point values (@pxref{Arbitrary +Precision Integers}). + +This function is a @code{gawk} extension. It is not available in +compatibility mode (@pxref{Options}). + @item @code{exp(@var{x})} @cindexawkfunc{exp} @cindex exponent @@ -26651,8 +26669,8 @@ When called this way, @command{gawk} ``pretty prints'' the program into @file{awkprof.out}, without any execution counts. @quotation NOTE -The @option{--pretty-print} option still runs your program. -This will change in the next major release. +Once upon a time, the @option{--pretty-print} option would also run +your program. This is is no longer the case. @end quotation @c ENDOFRANGE awkp @c ENDOFRANGE proawk @@ -29651,6 +29669,32 @@ to just use the following: gawk -M 'BEGIN @{ n = 13; print n % 2 @}' @end example +When dividing two arbitrary precision integers with either +@samp{/} or @samp{%}, the result is typically an arbitrary +precision floating point value (unless the denominator evenly +divides into the numerator). In order to do integer division +or remainder with arbitrary precision integers, use the built-in +@code{div()} function (@pxref{Numeric Functions}). + +You can simulate the @code{div()} function in standard @command{awk} +using this user-defined function: + +@example +# div --- do integer division + +function div(numerator, denominator, result, i) +@{ + split("", result) + + numerator = int(numerator) + denominator = int(denominator) + result["quotient"] = int(numerator / denominator) + result["remainder"] = int(numerator % denominator) + + return 0.0 +@} +@end example + @node POSIX Floating Point Problems @section Standards Versus Existing Practice @@ -35754,6 +35798,8 @@ The generated Info file for The @command{troff} source for a manual page describing the @command{igawk} program presented in @ref{Igawk Program}. +(Since @command{gawk} can do its own @code{@@include} processing, +neither @command{igawk} nor @file{igawk.1} are installed.) @item doc/Makefile.in The input file used during the configuration process to generate the @@ -35798,8 +35844,6 @@ source file for this @value{DOCUMENT}. It also contains a @file{Makefile.in} fil @file{Makefile.am} is used by GNU Automake to create @file{Makefile.in}. The library functions from @ref{Library Functions}, -and the @command{igawk} program from -@ref{Igawk Program}, are included as ready-to-use files in the @command{gawk} distribution. They are installed as part of the installation process. The rest of the programs in this @value{DOCUMENT} are available in appropriate @@ -36845,9 +36889,10 @@ mail at the Internet address noted previously. If you find bugs in one of the non-Unix ports of @command{gawk}, please send an electronic mail message to the person who maintains that port. They -are named in the following list, as well as in the @file{README} file in the @command{gawk} -distribution. Information in the @file{README} file should be considered -authoritative if it conflicts with this @value{DOCUMENT}. +are named in the following list, as well as in the @file{README} file +in the @command{gawk} distribution. Information in the @file{README} +file should be considered authoritative if it conflicts with this +@value{DOCUMENT}. The people maintaining the non-Unix ports of @command{gawk} are as follows: @@ -36875,7 +36920,8 @@ John Malmberg, @EMAIL{wb8tyw@@qsl.net,wb8tyw at qsl.net}. @end multitable If your bug is also reproducible under Unix, please send a copy of your -report to the @EMAIL{bug-gawk@@gnu.org,bug-gawk at gnu dot org} email list as well. +report to the @EMAIL{bug-gawk@@gnu.org,bug-gawk at gnu dot org} email +list as well. @c ENDOFRANGE dbugg @c ENDOFRANGE tblgawb |