[SCM] GNU Autoconf source repository branch, master, updated. v2.65-66-g41a1636

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU Autoconf source repository".

http://git.sv.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=41a163620f7d4803f7e649e70b386720b8135313

The branch, master has been updated
       via  41a163620f7d4803f7e649e70b386720b8135313 (commit)
      from  5dc7189c00f37f9542ad8dba0c9266d372b0e117 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit 41a163620f7d4803f7e649e70b386720b8135313
Author: Eric Blake <[email protected]>
Date:   Tue May 11 08:00:56 2010 -0600

    Mention how to silence program probes.
    
    * doc/autoconf.texi (File Descriptors): Document how to silence a
    program probe.
    
    Signed-off-by: Eric Blake <[email protected]>

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog         |    6 ++++++
 doc/autoconf.texi |   12 ++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 454f5aa..8b4c0f4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-05-11  Eric Blake  <[email protected]>
+
+	Mention how to silence program probes.
+	* doc/autoconf.texi (File Descriptors): Document how to silence a
+	program probe.
+
 2010-04-26  Ralf Wildenhues  <[email protected]>
 
 	Error and warning message formatting cleanups.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index d6a08bc..2873578 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -14793,6 +14793,18 @@ must be done @emph{inside} the command substitution.  When running
 @samp{: `cd /zorglub` 2>/dev/null} expect the error message to
 escape, while @samp{: `cd /zorglub 2>/dev/null`} works properly.
 
+On the other hand, some shells, such as Solaris or FreeBSD
+@command{/bin/sh}, warn about missing programs before performing
+redirections.  Therefore, to silently check whether a program exists, it
+is necessary to perform redirections on a subshell:
+
+@example
+$ @kbd{/bin/sh -c 'nosuch 2>/dev/null}
+nosuch: not found
+$ @kbd{/bin/sh -c '(nosuch) 2>/dev/null}
+$ @kbd{bash -c 'nosuch 2>/dev/null'}
+@end example
+
 FreeBSD 6.2 sh may mix the trace output lines from the statements in a
 shell pipeline.
 


hooks/post-receive
-- 
GNU Autoconf source repository