Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!news.funet.fi!hydra!cc.helsinki.fi!wirzenius
From: wirzenius@cc.helsinki.fi (Lars Wirzenius)
Newsgroups: comp.lang.c
Subject: Re: External Functions
Message-ID: <1991Mar16.125116.5560@cc.helsinki.fi>
Date: 16 Mar 91 12:51:16 GMT
References: <8146@rsiatl.Dixie.Com>
Organization: University of Helsinki
Lines: 20

In article <8146@rsiatl.Dixie.Com>, stan@Dixie.Com (Stan Brown) writes:
[Edited for brevity --Lars Wirzenius]
> 	Which of the folowing would be better & why
(1)
> 	extern void foo();
> 	void func1() { ... }
> 	void func2() { ... }
(2)
> 	void func1() { extern void foo(); ... }
> 	void func2() { extern void foo(); ... }

(1) is better, since the declaration needs to be written only once, so
there is less of a chance to introduce bugs when (not if) you change the
function declaration. You could improve on (1) by putting its
declaration (prototype if you have an ANSI compiler) into a header file,
and #including that into any source file that calls foo, and also into
the file that defines it (this is a handy way to ensure that
declarations and definitions stay in sync).
-- 
Lars Wirzenius    wirzenius@cc.helsinki.fi