Path: utzoo!utgpu!water!watmath!clyde!rutgers!mit-eddie!husc6!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: extern
Keywords: extern
Message-ID: <7150@brl-smoke.ARPA>
Date: 21 Jan 88 15:55:29 GMT
References: <17428@topaz.rutgers.edu> <7123@brl-smoke.ARPA> <4405@garfield.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Distribution: na
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 17

In article <4405@garfield.UUCP> john13@garfield.UUCP (John Russell) writes:
-In article <7123@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
-] Not quite either.  There are two possible methods of implementation
-] of extern data in C, but the model you should think of is:  If it
-] says "extern", it is a reference to something allocated elsewhere;
-That is the way you should think about it, but if you do something like this:
-file 1 -
-int fou;
[I assume "foo" was intended]
-file 2 -
-extern int foo;
-foo = 1;
-then at least some compilers will run this properly (no warnings even).

PLEASE don't do this.  A compiler is not obliged to make this example
"work".  That is why you should think the way I said; C compilers are
obliged to always make that approach work right.