Hi Eric, somewhat older mail:
* Eric Blake wrote on Wed, Oct 29, 2008 at 04:53:54AM CET: > > I'm applying the following patch, which reduces the number of forks needed > during the better shell search portion of M4sh scripts. > > Meanwhile, are there any shells where a message escapes when attempting to > redirect stderr of a program that can't be executed? More to the point, > is this silent: > > echo 'echo hi' > foo > chmod a-x foo > echo '...' | ./foo 2>/dev/null > > or must we use (./foo) in order to squelch messages from some shell in the > case where ./foo is not executable or not a valid binary image? I'm > asking because _AS_RUN is currently using the subshell, after already > verifying that 'test -f shell' passes (but doesn't do 'test -x shell'), > and I'd like to remove the subshell if it is safe. I haven't found a shell that needs this subshell, but this: $ echo '...' | ./foo 2>/dev/null causes this output from some bash versions: | bash: echo: write error: Broken pipe Of course that output isn't avoided by putting ./foo in a subshell, and I think it doesn't affect the changed code, either, but I thought I'd mention it. Cheers, Ralf
