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From: gea@Iago.Caltech.EDU (Gary Ansok)
Newsgroups: comp.lang.c
Subject: External variable declarations
Message-ID: <8056@brl-adm.ARPA>
Date: Fri, 26-Jun-87 16:10:37 EDT
Article-I.D.: brl-adm.8056
Posted: Fri Jun 26 16:10:37 1987
Date-Received: Sat, 27-Jun-87 10:36:37 EDT
Sender: news@brl-adm.ARPA
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At least according to K&R (p. 77), there is no need for fancy #define's to
make sure that global variables are declared and initialized properly.

header.h:

struct foo { ... };

extern int var1;
extern struct foo var2;


file.c:

#include "header.h"

int var1 = 42;
struct foo var2 = { ... };

The disadvantage is that the type of a variable is duplicated in two places
(some mismatches will be detected by the compiler); however, you get cleaner
(and easier to write and understand) code which is, I think, less easy to
misdeclare (what happens if two or zero modules define __GLOB__? -- not that
this is damnfoolproof).  You can also spread the initializations around among
modules if you think of a global variable as "owned" by one module and "used"
by other modules (if your program works that way).

Like many other things in programming, especially C programming, this is
something where we can argue for hours.  But I thought I'd present a case
with no messy #defines or #ifs.

	Gary Ansok
	gea@romeo.caltech.edu   -- or --   ansok@scivax.arpa