Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!rex!cleeland
From: cleeland@rex.cs.tulane.edu (Chris Cleeland)
Newsgroups: comp.unix.questions
Subject: Re: memcpy != bcopy (Was Re: bcopy() bzero())
Message-ID: <2177@rex.cs.tulane.edu>
Date: 12 Feb 90 04:55:55 GMT
References: <11387@attctc.Dallas.TX.US> <4601@orion.cf.uci.edu> <497@thirdi.UUCP>
Reply-To: cleeland@rex.UUCP (Chris Cleeland)
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Organization: Computer Science Dept., Tulane Univ., New Orleans, LA
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In article <497@thirdi.UUCP> peter@thirdi.UUCP (Peter Rowell) writes:
>echarne@orion.oac.uci.edu (Eli B. Charne) writes:
>
>WARNING!  memcpy is NOT the same as bcopy!!!!
>This is the source of an *amazing* array of hard-to-find bugs!
>bcopy correctly handles overlapping memory moves; memcpy does not.
>
>If you code does not expect/require (either deliberately or accidentally)
>that overlapping moves be done correctly, then it is "safe" to claim
>the two are equivalent.
>
>PS. the first two arguments to bcopy are reversed in memcpy.

What he said.

Also, though, memmove() *does* properly handle overlapping areas (at
least according to K&R2 -- my system has bcopy).  Parameters are the
same as memcopy()
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