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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.lang.c,comp.unix.questions
Subject: csh, exit, &&, || (was Re: exit(-1), 0 is sometimes magic)
Message-ID: <10318@mimsy.UUCP>
Date: 24 Jan 88 04:43:36 GMT
References: <502@cresswell.quintus.UUCP> <6935@brl-smoke.ARPA> <1179@wjvax.UUCP> <310@fig.bbn.com>
Followup-To: comp.unix.questions
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 23
Keywords: exit, zero, shells

(I overrode Rich's followup-to header, since there are buggy csh's out
there.)
In article <310@fig.bbn.com> rsalz@bbn.com (Rich Salz) writes:
>The use of && and || in csh is the opposite of that in /bin/sh.
>	/bin/sh -c "/bin/test -d foo || mkdir foo"
>Means if the foo directory doesn't exist, make it. ...
>	/bin/csh -c "/bin/test -d foo || mkdir foo"
>will never make the directory, or mkdir will spit if it already exists.

BUZZ!

Sorry, contestant number 3.

:-)

Old versions of the C shell did indeed have this bug.  It has been
fixed for years.  If your C shell does this, complain to your vendor
(or upgrade from 3BSD!).  I believe the documentation has always
claimed that the C shell's `&&' and `||' constructs work in the
same way as the Bourne shell's.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris