Path: utzoo!utgpu!water!watmath!dalcs!garfield!john13
From: john13@garfield.UUCP (John Russell)
Newsgroups: comp.lang.c
Subject: Re: extern
Keywords: extern qualifier
Message-ID: <4405@garfield.UUCP>
Date: 19 Jan 88 14:11:53 GMT
References: <17428@topaz.rutgers.edu> <7123@brl-smoke.ARPA>
Reply-To: john13@garfield.UUCP (John Russell)
Distribution: na
Organization: Memorial University of Newfoundland, St. John's
Lines: 28

In article <7123@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
]>Is the compiler allocating space for these variables, or is it just
]>identifying thier names as a reference to something from another
]>source file, to be resolved at link-time?
]
]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;
...

file 2 -
extern int foo;
...
foo = 1;

then at least some compilers will run this properly (no warnings even).

John
-- 
"A Chinese soldier in Tibet who tried to tear off a British woman's Sergeant
 Bilko T-shirt has become the first known case of someone mistaking Phil
 Silvers for the Dalai Lama."
				-- Toronto Globe & Mail, Nov. 14/87