Re: [Qemu-devel] [PATCH 2/4] Add cleanup function

[Ryan Harper <ryanh@us.ibm.com>]

* Eric Blake <eblake@redhat.com> [2012-01-17 16:03]:
> On 01/16/2012 10:16 AM, Ryan Harper wrote:
> >>>  if test -z "$1" -o -z "$2"; then
> >>>      echo "Usage: $0 QEMU TEST1 [TEST2 ...]"
> >>> +    cleanup
> >>>      exit 1
> >>
> >> Is it worth using 'trap cleanup 0' to install the cleanup handler up
> >> front, instead of modifying all exit call sites?
> > 
> > I thought about that, but it seemed to require switching to /bin/bash
> 
> Not really.
> 
> > 
> > and I know Anthony had written the scripts carefully to be /bin/sh.
> 
> POSIX requires /bin/sh to support 'trap cleanup 0', and I don't know of

I was using trap cleanup SIGINT; which /bin/sh didn't like:

(finalgravity) qemu-test % ./qemu-test ~/work/git/qemu/x86_64-softmmu/qemu-system-x86_64 tests/virtio-serial.sh 
trap: SIGINT: bad trap

but with 0 instead, that seems to work.

> any counter-example shells that fail to do this.  There are non-POSIX
> shells where installing a trap 0 handler from inside a function body
> invokes the handler upon exiting the function, instead of exiting the
> overall script, but even Solaris /bin/sh knows how to correctly handle a
> trap 0 handler installed outside of any function calls.
> 
> https://www.gnu.org/software/autoconf/manual/autoconf.html#trap
> 
> -- 
> Eric Blake   eblake@redhat.com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
> 



-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com