Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!apple!sun-barr!newstop!texsun!letni!doug
From: doug@letni.UUCP (Doug Davis)
Newsgroups: comp.std.c
Subject: Re: Out-of-bounds pointers
Message-ID: <4199@letni.UUCP>
Date: 4 Oct 89 15:31:26 GMT
References: <1009@mtxinu.UUCP>
Reply-To: doug@letni.LawNet.Com (Doug Davis)
Organization: Logic Process  Dallas, Texas.
Lines: 24

In article <1009@mtxinu.UUCP> ed@mtxinu.COM (Ed Gould) writes:
>	void
>	f() {
>		char bug[100];
             ^^^^^^^^^^  I assume you mean buf here, right?
>		char *p;
>
>		p = buf;
>
>		p--;	/* p contains an illegal value: &buf[-1] */
        ^^^ Opps,  You have now entered the land of illegal addresses,
                   normally called the twilight zone, incrementing the
                   pointer is no longer guarenteed to be == &buf[0], that
                   is installation dependent.  Most likely it will == something
                   really weird and you get a core dump.  Which one you get
                   is left as an exercise to the reader.
    
                 
doug
__
Doug Davis/1030 Pleasant Valley Lane/Arlington/Texas/76015/817-467-3740
{sys1.tandy.com, motown!sys1, uiucuxc!sys1 lawnet, attctc, texbell} letni!doug
"ack, pifft!  <ZOT> RRREEEEAAAAAWWWWOOOOOO!" -- Sound effects from the "Bill
The Cat'lprod(TM)" Commercial,  Available in better hardware stores near you.