Path: utzoo!mnetor!uunet!husc6!purdue!umd5!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: exit(-1)
Message-ID: <10312@mimsy.UUCP>
Date: 23 Jan 88 06:32:06 GMT
References: <502@cresswell.quintus.UUCP> <6935@brl-smoke.ARPA> <1179@wjvax.UUCP> <1240@nmtsun.nmt.edu>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 33

>In article <10237@mimsy.UUCP> I claimed that (in a better world)
>>Unix, by virtue of being the first system to implement the language,
>>is privileged: it gets to take the argument to exit() and pass it
>>back to the calling program.  Other systems might have to convert
>>the argument to 0 => success, anything else => unspecified failure.

In article <1240@nmtsun.nmt.edu> hydrovax@nmtsun.nmt.edu (M. Warner
Losh) writes:
>    The UNIX operating system does not work this way.  The shells that
>surround it DO.

This is true, and entirely irrelevant.  Since the shells that
surround it assume that 0 => success, anything else => unspecified
failure, `Unix' (whatever that is) assumes 0 => success, anything
else => unspecified failure.  While there are programs that do not
follow this convention, they are in the minority (and, incidentally,
they are being weeded out, at least in 4BSD: /etc/dump recently
changed to exit(0) instead of exit(1) on success).

In other words, all we have to do is take this convention and
establish it as a standard across all systems (including Unix!---where
it is implemented entirely outside of the kernel, but it *is*
implemented), and *everything* *works*.  We have gained portability
and lost nothing.

>The basic argument is this:  Since UNIX had it first, should all other
>OS's be forced to use that convention?

Since portability is gained, and nothing is lost, *YES*.  This is
then a *language* convention, *not* an operating system convention.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris