Re: [question] && chaining vs shell loops

From: Jeff King <peff@peff.net>
Date: Mar 29, 2015, 17:43 UTC
Message-ID: <20150329174312.GA6680@peff.net>
In-Reply-To: <874mp3948k.fsf@igel.home>

On Sun, Mar 29, 2015 at 06:07:39PM +0200, Andreas Schwab wrote:

Show 10 quoted lines

> Max Kirillov <max@max630.net> writes:
> 
> > As far as I can see, loops in shell ignore non-zero exit
> > codes of the bodies which are not last. For example, exit
> > code of command 'for f in false true; do $f; done' is 0,
> > even if there was false.
> 
> There is nothing special with loops, that's how the exit code of
> compound commands is defined in general: it's the exit code of the last
> executed command.

Yes, but that makes it problematic if you want to know if any of the loop iterations failed. Doing:

  for f in false true; do $f || break; done

doesn't work, because the "break" has exit code 0. Doing:

  (for f in false true; do $f || exit 1; done)

works. In our test scripts, it is also OK to just "return 1", because the test snippets execute inside a function.

If you have other solutions, I'd love to hear them. I just fixed several of these loops recently, and I couldn't come up with anything more clever.

-Peff