Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!uw-beaver!ssc-vax!bcsaic!paula
From: paula@bcsaic.UUCP (Paul Allen)
Newsgroups: comp.os.minix
Subject: Re: NULL
Message-ID: <50235@bcsaic.UUCP>
Date: 24 Jun 91 16:11:06 GMT
References: <33822@usc.edu>
Organization: Boeing Computer Services AI Center, Seattle
Lines: 39

In article <33822@usc.edu> kjh@pollux.usc.edu (Kenneth J. Hendrickson) writes:
>*** BUG FIX ***
>
>In /usr/include/stdio.h, #define NULL 0
>In /usr/include/*.h (all others), #define NULL ((void *)0)
>
>stdio.h should be updated asap.
>
>If I'm wrong about this, or if this will break anything, please let me
>know.

I think you're wrong, but I'm not enough of a wizard to say so with
authority.  In my archives, I find two articles explaining why NULL
is zero.  One, posted by Cris Torek back in early 1988, is quite long
and has been reposted at least once in response to continuing calls
to change the definition of NULL.  The other, by Steve Jenkins of
Caltech/JPL, is much more concise, just as convincing, and refers
interested parties to the FAQ for comp.lang.c.  Apparently, the C
wizards have been discussing this question for years, and have
concluded that the only correct thing to do is to define NULL as
the integer consant zero and cast it to an appropriate pointer type
when it is used.

Does anybody out there have a copy of the comp.lang.c Frequently-
Asked-Questions list?  If so, would you please post the section
dealing with NULL so that we may all benefit from the wisdom of the
experts?  I'd do it myself, but I must admit I've never been able
to muster the patience to wade through c.l.c.  :-)

Paul Allen





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Paul L. Allen                       | pallen@atc.boeing.com
Boeing Advanced Technology Center   | ...!uw-beaver!bcsaic!pallen