NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/std/c/665

Internet Message Format | 1996-08-06 | 2KB

Path: lyra.csx.cam.ac.uk!nmm1
From: [e-mail] (Nick Maclaren)
Newsgroups: comp.std.c
Subject: Re: EXIT_SUCCES != EXIT_FAILURE?
Date: 28 Mar 1996 10:52:05 GMT
Organization: University of Cambridge, England
Message-ID: <4jdr0l$[e-mail]>
References: <tompa.827763954@news> <4j7p4p$[e-mail]>
NNTP-Posting-Host: ursa.cus.cam.ac.uk

In article <4j7p4p$[e-mail]>, [e-mail]   (Bill McCarthy) writes:
|> In <tompa.827763954@news>, [e-mail] (Thomas Padron-McCarthy) writes:
|> >
|> >Many of the students in a C course I teach have started to use
|> >EXIT_SUCCESS and EXIT_FAILURE as return values from functions
|> >(other than main).
|> >
|> >I don't like this new practice, but questions of style are difficult.
|> >So I wonder: Does the standard guarantee that EXIT_SUCCESS and
|> >EXIT_FAILURE are different?
|>
|> Not only are they not guaranteed to be different.  EXIT_SUCCESS is
|> not guaranteed to be zero, and EXIT_FAILURE is not guaranteed to
|> be different from 0.  They are implementation defined and should
|> only be used as an argument to exit() or in a return from main().

This is a little harsh.  While they are not defined to be different,
they will be the same only on a very inferior implementation indeed!
And few students are capable of writing code that can defend itself
against such implementations.

Also, if they use them CONSISTENTLY, it doesn't matter that their
values are not defined.  I would regard this practice as perfectly
reasonable, in context, though I have no intention of adopting it
myself.

To put things in context, do you expect all students to write code
assuming the compilation and execution environments differ in their
character sets and both fixed- and floating-point arithmetic?


Nick Maclaren,
University of Cambridge Computer Laboratory,
New Museums Site, Pembroke Street, Cambridge CB2 3QG, England.
Email:  [e-mail]
Tel.:  [phone]    Fax:  [phone]