On 10/27/2010 09:30 PM, Paul Eggert wrote: > OpenBSD /bin/sh, and some other sh variants, squirrel away file > descriptors before closing them.
ALL shells squirrel away file descriptors before closing them for the duration of a builtin command, if there is a chance that a later shell command will be executed that no longer needs the temporary closure. It's just that ksh is a bit smarter about recognizing the last command in a script, and doesn't squirrel away when there are no subsequent commands that could possible need the fd. But as was pointed out on the dash list, this means that ksh is buggy when there is an exit trap installed such that there really ARE commands after the last command of the script: $ ksh93 -c ':; trap "echo hi" EXIT >/dev/null' $ All other shells output hi, because the redirection to /dev/null should only have lasted for the duration of installing the trap, and not for the actual execution of the trap. -- Eric Blake ebl...@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org
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