Re: [PATCH] Allow shell scripts to run with non-Bash /bin/sh

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 22, 2007, 08:32 UTC
Message-ID: <7vtzpnf6c9.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20070922035434.GA99140@void.codelabs.ru>

Eygene Ryabinkin <rea-git@codelabs.ru> writes:

> OK, you're right.  Especially if /bin/sh from Solaris and OpenBSD
> are working and they are not Bash.  But I would not tell that
> the shell is broken now -- I had not seen the POSIX specification.
> Does it specifies how the shell should work in this case?

I have always been assuming it to be the case (this construct is not my invention but is an old school idiom I just inherited from my mentor) and never looked at the spec recently, but I re-read it just to make sure. The answer is yes.

Visit http://www.opengroup.org/onlinepubs/000095399/ and follow "Shell and Utilities volume (XCU)" and then "Case conditional construct".

    Exit Status

    The exit status of case shall be zero if no patterns are
    matched. Otherwise, the exit status shall be the exit status of
    the last command executed in the compound-list.

So, as David suggests, if

        false
        case Ultra in
        Super) false ;;
        Hyper) true ;;
        esac && echo case returned ok

does not say "case returned ok", then the shell has a bit of problem.