Path: utzoo!mnetor!uunet!nuchat!sugar!peter
From: peter@sugar.UUCP (Peter da Silva)
Newsgroups: comp.lang.c
Subject: Re: exit(-1)
Message-ID: <1365@sugar.UUCP>
Date: 6 Jan 88 03:48:16 GMT
References: <502@cresswell.quintus.UUCP>
Organization: Sugar Land UNIX - Houston, TX
Lines: 26

In article ... ok@quintus.UUCP (Richard A. O'Keefe) writes:
> [exit()]
>
> The VAX-11 C manual explicitly says that the argument of exit()
> should be 0 or a value errno might have.
> 
> The Oct86 dpANS said only that 0 arguments indicate success and
> non-0 arguments indicate failure in some system-dependent way.
> 
> Except where you are writing code for a specific system (say you
> have #if cases for MVS, VMS, and UNIX) it seems like a good idea
> to pass only 0 or 1 to exit().

I like passing -1 because:

	It's negative (some systems use the sign bit to specify true/false).
	It's odd (some systems use the low bit for the same purpose).
	All bits are set (some systems do ANDS and ORS using & and |).
	If it's truncated, it's large (some systems use small values for
		warnings, and large ones for fatal errors).

I've never had a system treat "-1" as a successful result. I have had one
ignore a return code of 1.
-- 
-- Peter da Silva  `-_-'  ...!hoptoad!academ!uhnix1!sugar!peter
-- Disclaimer: These U aren't mere opinions... these are *values*.