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From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: Referencing NULL pointers
Message-ID: <2219@auspex.auspex.com>
Date: 11 Jul 89 19:10:05 GMT
References: <19367@paris.ics.uci.edu> <1891@auspex.auspex.com> <32UP02Eg3d=801@amdahl.uts.amdahl.com>
Reply-To: guy@auspex.auspex.com (Guy Harris)
Organization: Auspex Systems, Santa Clara
Lines: 13

>I would say that the code is valid.

And you'd be wrong in saying so.  The ANSI C standard makes it quite
clear that dereferencing null pointers is a no-no, and K&R never said it
was valid.

For reasons cited in my posting, even if it *doesn't* cause a
segmentation violation, the behavior isn't guaranteed; on such systems,
you'd be most likely to get whatever stuff was lying around location 0
in your address space, and that can be almost anything. 

"valid" doesn't mean "anything you can get away with without a core
dump".