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From: grantk@manta.NOSC.MIL (Kelly J. Grant)
Newsgroups: comp.lang.c
Subject: external definition problems...
Message-ID: <2080@manta.NOSC.MIL>
Date: 26 Jun 91 15:02:17 GMT
Article-I.D.: manta.2080
Organization: Computer Sciences Corporation
Lines: 23

I'm working on 4.2BSD on a Sun.  In one module I have a character array
declared, 'char foo[20+1];'.  In another module, I refer to foo using
extern, ie.,'extern char *foo', and then attempted to use it in a 
printf(), which summarily caused a core dump.  When I changed the
reference to 'extern char foo[]', it worked properly.

K&R2 does not seem to address this directly.  I read about external 
definitions in the appendix, and the entire pointer chapter, but
it does not reference this exact situation.

Does anyone out there have a good explanation why the char * failed ?
I know that a pointer can be treated differently (ie, incremented),
but as an argument to a function it should not matter.  What is
actually occurring during the failure ?

Many thanks in advance

Kelly
-- 
Kelly Grant        grantk@manta.nosc.mil   (619) 225-2508
Computer Sciences Corp          ^^^^^^^^ Important: manta.UUCP won't get to me
4045 Hancock Street      "If you are given lemons.....see if you can trade for
San Diego, CA 92110       chocolate" - me