On 07/04/2012 09:37 AM, Rainer Blome wrote: > > * Different POSIX shell implementations are free to behave > differently, because the behavior is not specified exactly.
Actually, that's where you are wrong. POSIX _does_ specify bash's current behavior (in fact, bash changed behavior to match POSIX) > http://pubs.opengroup.org/onlinepubs/009695399/utilities/set.html http://austingroupbugs.net/view.php?id=52 which even includes this example: Application writers should avoid relying on set -e within functions. For example, in the following script: set -e start() { some_server echo some_server started successfully } start || echo >&2 some_server failed the -e setting is ignored within the function body (because the function is a command in an AND-OR list other than the last). Therefore if some_server fails, the function carries on to echo "server started successfully", and the exit status of the function is zero (which means "server failed" is not output). > * Some shell implementations *do* behave differently from Bash > in this regard. At least on AIX, ksh and sh do so. Only because they haven't been patched to obey POSIX yet. > > * The average shell programmer probably seldomly encounters > the difference, because it rarely matters. Actually, the average shell programmer should avoid 'set -e', because of its historical warts and non-intuitive behavior. -- Eric Blake ebl...@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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