Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uflorida!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.unix.questions
Subject: Re: NULL as a string terminator
Message-ID: <13484@smoke.BRL.MIL>
Date: 5 Aug 90 02:20:26 GMT
References: <9220003@hpldsla.sid.hp.com> <707@mtune.ATT.COM> <26593@nigel.ee.udel.edu>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 12

In article <26593@nigel.ee.udel.edu> gdtltr@freezer.it.udel.edu (Gary Duzan) writes:
>=>	char command[15];
>=>	command[strlen(command)-1]=NULL; /* chop off the \n */
>   Pardon me for reopening the NULL discussion, but won't this give a warning
>if NULL is #defined (void *) 0? If it doesn't, should it? Assigning a pointer
>to a char is certainly a questionable thing to do.

You're correct; the example code would happen to work with the traditional
definition of NULL as plain 0, but not if it's defined as ((void*)0).  In
general it is a mistake to use the NULL macro for any purpose other than a
stand-in for a null pointer constant.  In the example code, either 0 or '\0'
would be a reasonable replacement for NULL.