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Diffstat (limited to 'doc/gawk.texi')
| -rw-r--r-- | doc/gawk.texi | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/doc/gawk.texi b/doc/gawk.texi index 835dbc00..63dfcb9d 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -20,7 +20,7 @@ @c applies to and all the info about who's publishing this edition @c These apply across the board. -@set UPDATE-MONTH November, 2012 +@set UPDATE-MONTH December, 2012 @set VERSION 4.0 @set PATCHLEVEL 2 @@ -15990,7 +15990,7 @@ which discusses this feature in more detail and gives an example. @cindex extensions, common@comma{} @code{fflush()} function Flush any buffered output associated with @var{filename}, which is either a file opened for writing or a shell command for redirecting output to -a pipe or coprocess. @value{COMMONEXT}. +a pipe or coprocess. @cindex portability, @code{fflush()} function and @cindex buffers, flushing @@ -16007,25 +16007,27 @@ buffers its output and the @code{fflush()} function forces @command{gawk} to flush its buffers. @code{fflush()} was added to Brian Kernighan's -version of @command{awk} in 1994; it is not part of the POSIX standard and is -not available if @option{--posix} has been specified on the -command line (@pxref{Options}). +version of @command{awk} in 1994. +For over two decades, it was not part of the POSIX standard. +As of December, 2012, it was accepted for +inclusion into the POSIX standard. +See @uref{http://austingroupbugs.net/view.php?id=634, the Austin Group website}. -@cindex @command{gawk}, @code{fflush()} function in -@command{gawk} extends the @code{fflush()} function, as follows: If there +POSIX standardizes @code{fflush()} as follows: If there is no argument, or if the argument is the null string (@w{@code{""}}), -@command{gawk} flushes the buffers for @emph{all} open output files -and pipes. Brian Kernighan's @command{awk} also works this way. +then @command{awk} flushes the buffers for @emph{all} open output files +and pipes. @quotation NOTE -Prior to version @strong{FIXME: VERSION}, @command{gawk} +Prior to version 4.0.2, @command{gawk} would flush only the standard output if there was no argument, and flush all output files and pipes if the argument was the null string. This was changed in order to be compatible with Brian Kernighan's @command{awk}, in the hope that standardizing this -feature in POSIX would then be easier. +feature in POSIX would then be easier (which indeed helped). -You can use @samp{fflush("/dev/stdout")} if you wish to flush +With @command{gawk}, +you can use @samp{fflush("/dev/stdout")} if you wish to flush only the standard output. @end quotation @@ -16033,7 +16035,7 @@ only the standard output. @c @cindex warnings, automatic @cindex troubleshooting, @code{fflush()} function @code{fflush()} returns zero if the buffer is successfully flushed; -otherwise, it returns @minus{}1. +otherwise, it returns non-zero (@command{gawk} returns @minus{}1). In the case where all buffers are flushed, the return value is zero only if all buffers were flushed successfully. Otherwise, it is @minus{}1, and @command{gawk} warns about the problem @var{filename}. @@ -16141,7 +16143,7 @@ it is all buffered and sent down the pipe to @command{cat} in one shot. @cindex output, buffering The @code{fflush()} function provides explicit control over output buffering for -individual files and pipes. However, its use is not portable to many other +individual files and pipes. However, its use is not portable to many older @command{awk} implementations. An alternative method to flush output buffers is to call @code{system()} with a null string as its argument: @@ -32274,6 +32276,7 @@ The use of @code{func} as an abbreviation for @code{function} @item The @code{fflush()} built-in function for flushing buffered output (@pxref{I/O Functions}). +As of December 2012, this function is now standardized by POSIX. @ignore @item @@ -32626,7 +32629,6 @@ the three most widely-used freely available versions of @command{awk} @item @code{nextfile} statement @tab X @tab X @tab X @item @code{delete} without subscript @tab X @tab X @tab X @item @code{length()} of an array @tab X @tab @tab X -@item @code{fflush()} function @tab X @tab X @tab X @item @code{BINMODE} variable @tab @tab X @tab X @end multitable |