* src/sort.c (MAX_FORK_RETRIES_COMPRESS, MAX_FORK_RETRIES_DECOMPRESS):

In pipe_fork callers, use these named constants, not "2" and "8".
(proctab, nprocs): Declare to be "static".
(pipe_fork) [lint]: Initialize local, pid,
to avoid unwarranted may-be-used-uninitialized warning.
(create_temp): Use the active voice.  Describe parameters, too.

2007-01-21  James Youngman  <jay@gnu.org>

Centralize all the uses of sigprocmask().  Don't restore an invalid
saved mask.
* src/sort.c (enter_cs, leave_cs): New functions for protecting
code sequences against signal delivery.
* (exit_cleanup): Use enter_cs and leave_cs instead of
calling sigprocmask directly.
(create_temp_file, pipe_fork, zaptemp): Likewise

2007-01-21  Dan Hipschman  <dsh@linux.ucla.edu>

Add compression of temp files to sort.
* NEWS: Mention this.
* bootstrap.conf: Import findprog.
* configure.ac: Add AC_FUNC_FORK.
* doc/coreutils.texi: Document GNUSORT_COMPRESSOR environment
variable.
* src/sort.c (compress_program): New global, holds the name of the
external compression program.
(struct sortfile): New type used by mergepfs and friends instead
of filenames to hold PIDs of compressor processes.
(proctab): New global, holds compressor PIDs on which to wait.
(enum procstate, struct procnode): New types used by proctab.
(proctab_hasher, proctab_comparator): New functions for proctab.
(nprocs): New global, number of forked but unreaped children.
(reap, reap_some): New function, wait for/cleanup forked processes.
(register_proc, update_proc, wait_proc): New functions for adding,
modifying and removing proctab entries.
(create_temp_file): Change parameter type to pointer to file
descriptor, and return type to pointer to struct tempnode.
(dup2_or_die): New function used in create_temp and open_temp.
(pipe_fork): New function, creates a pipe and child process.
(create_temp): Creates a temp file and possibly a compression
program to which we filter output.
(open_temp): Opens a compressed temp file and creates a
decompression process through which to filter the input.
(mergefps): Change FILES parameter type to struct sortfile array
and update access accordingly.  Use open_temp and reap_some.
(avoid_trashing_input, merge): Change FILES parameter like
mergefps and call create_temp instead of create_temp_file.
(sort): Call create_temp instead of create_temp_file.
Use reap_some.
(avoid_trashing_input, merge, sort, main): Adapt to mergefps.

1 files changed, 13 insertions, 0 deletions

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 89e97d8bc..1abf45dbf 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -3411,6 +3411,19 @@ value as the directory for temporary files instead of @file{/tmp}.  The
 @option{--temporary-directory} (@option{-T}) option in turn overrides
 the environment variable.
 
+@vindex GNUSORT_COMPRESSOR
+To improve performance when sorting very large files, GNU sort will,
+by default, try to compress temporary files with the program
+@file{gzip}.  The environment variable @env{GNUSORT_COMPRESSOR} can be
+set to the name of another program to be used.  The program specified
+must compress standard input to standard output when no arguments are
+given to it, and it must decompress standard input to standard output
+when the @option{-d} argument is given to it.  If the program exits
+with nonzero status, sort will terminate with an error.  To disable
+compression of temporary files, set the variable to the empty string.
+Whitespace and the backslash character should not appear in the
+program name.  They are reserved for future use.
+
 
 The following options affect the ordering of output lines.  They may be
 specified globally or as part of a specific key field.  If no key