-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Stephane Chazelas on 10/29/2008 3:32 AM: >> Yes. For shell portability, I'll write the first line as >> : > stdout >> : > stderr >> >> though. > > Why?
It fails on old Ultrix sh, which can't redirect the same fd more than once in a single statement. But that platform is relatively dead these days. >> + ( $at_traceon; $1 ) >>"$at_stdout" 2>>"$at_stder1" > > I've not read the full code so I don't know what $1 may contain, > but I wonder whether eval "$1" shouldn't be preferable here (in > case $1 is meant to contain a shell command line as opposed to a > space separated list of wildcards). This is in the context of m4 macro-expanding text that ultimately results in shell code. $1 is an m4 argument that contains properly quoted shell code, and not a shell argument. >> - ( :; $1 ) >"$at_stdout" 2>"$at_stderr" >> + : >"$at_stderr" >> + ( :; $1 ) >>"$at_stdout" 2>>"$at_stderr" > > What's the ":;" for? A workaround to the bash 3.2 bug, fixed in bash32-030, where failure to use :; prior to a compound command (except for a subshell) meant that bash incorrectly returns status 0 if redirection fails. - -- Don't work too hard, make some time for fun as well! Eric Blake [EMAIL PROTECTED] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkkIVY0ACgkQ84KuGfSFAYD9CgCeKyNN2WOvf+WkfSKEYyYC0+/d IQ0AoJLaWtW/9nfIzQzozVaKONY67BwU =PYtJ -----END PGP SIGNATURE-----
