Re: [Libguestfs] [libnbd PATCH 16/18] tests/requires: wrap source code at 80 characters
On Wed, Apr 19, 2023 at 05:27:45PM +0200, Laszlo Ersek wrote:
> Yes, I noticed that too, but I assumed there was a finer point I
was
> missing. :/
Ah, it's not too relevant, but now I remember what was bothering me,
about "!": if you embed the original construct in a "set -e"
environment, it will exit with status 1 on the appropriate branch; but
if you embed the "! ..." construct, it won't exit!
Indeed, that's another reason to be cautious about ! at a top level.
Most uses of ! are inside conditionals (such as if ! ...; then' where
set -e already can't touch), whereas this snippet is indeed at a top
level,...
Anyway, the context is not like that here. We pass the command string to
system(), and I understand "set -e" is not in effect there.
...but you are correct that system() does not use 'set -e'
automatically. Then again, since shell snippes run in Makefile ARE
supposed to use implicit set -e, it never hurts to be vigilant about
context when looking at shell snippets embedded in a larger file.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org