[question] && chaining vs shell loops

[question] && chaining vs shell loops

[Max Kirillov]

Hi.

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.

How should one workaround it in test scripts, is there any
established approach?

-- 
Max

Re: [question] && chaining vs shell loops

[Andreas Schwab]

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.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: [question] && chaining vs shell loops

[Jeff King]

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

> 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

Re: [question] && chaining vs shell loops

[Max Kirillov]

On Sun, Mar 29, 2015 at 8:43 PM, Jeff King <peff@peff.net> wrote:
> In our test scripts, it is also OK to just "return 1", because
> the test snippets execute inside a function.

Thanks, sounds like a plan.

-- 
Max