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From: mcmahan@netcom.UUCP (Dave Mc Mahan)
Newsgroups: comp.sys.amiga.tech
Subject: Re: JRComm, VLT, Handshake
Message-ID: <15811@netcom.UUCP>
Date: 30 Oct 90 04:11:52 GMT
References: <458@faatcrl.UUCP> <15418@cbmvax.commodore.com> <466@faatcrl.UUCP>
Organization: Dave McMahan @ NetCom Services
Lines: 24
Distribution:


 In a previous article, jprad@faatcrl.UUCP (Jack Radigan) writes:
>andy@cbmvax.commodore.com (Andy Finkel) writes:
>
>>If your program breaks when location 0 is non NULL this means
>>you have an unitialized pointer somewhere in your program, and
>>are using memory you did not allocate (ie location 0)
>
>  Uh, according to K&R, NULL is a valid assignment for a pointer, so
>how is it unitialized?
>
>  But, my question is the NULL pointer itself, if NULL is a valid constant,
>then the location NULL should contain nothing either, right?

I don't think so.  Just because NULL is a valid initialization for a pointer
doesn't mean that it HAS to point to something legal.  After all, what is
your definition of legal?  K&R just states that all static and global variables
will default to NULL, I don't think it says anything about what the NULL
location has to contain.  It is also legal to set an integer pointer to an
odd address on the 68000 CPU.  Just don't try to use it though.    :-) 

>  -jack-

     -dave