Re: [PATCH] Fixed non portable use of expr and removed incorrect use of test -eq for string comparison

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 23, 2007, 09:25 UTC
Message-ID: <7vveb6txfc.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20070823090600.GB6573@informatik.uni-freiburg.de>

Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> writes:

Show 18 quoted lines

> Junio C Hamano wrote:
>> By the way, I do not know if the use of "which" there is
>> portable.  Have Solaris folks tried this program ever?
> I don't count myself to "Solaris folks", even though I still use it to
> read and write my email.  But anyhow I know some of the pitfalls...
>
> 	login@~ > /bin/bash --version
> 	GNU bash, version 3.00.16(1)-release (sparc-sun-solaris2.10)
> 	Copyright (C) 2004 Free Software Foundation, Inc.
>
> 	login@~ > /bin/bash
>
> 	zeisberg@login ~$ which httpd && echo successful
> 	no httpd in /home/zeisberg/bin /home/zeisberg/usr/bin /opt/bin
> 	/usr/local/graphics/bin /usr/local/gnu/bin /usr/local/bin
> 	/usr/local/X11R6/bin /usr/xpg4/bin /usr/bin /usr/ccs/bin /usr/sbin
> 	/usr/ucb /usr/openwin/bin
> 	successful

Thanks.  Somebody else tried:

	found=`which "$command"`
        if test -n "$found"
        then
        	... use $found as the full path to the command
	fi

and got burned because "no httpd in ..." comes to the stdout! I did not exactly recall if there was an issue with the exit status, but your demonstration shows that the status is also useless.

We _could_ do something ugly and pointless like:

	test -f `which "$command"`

but I'd say I prefer the alternative I sent out at that point.