Xref: utzoo comp.lang.c:16256 comp.sources.wanted:6365 comp.unix.xenix:4984
Newsgroups: comp.lang.c,comp.sources.wanted,comp.unix.xenix
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Looking for memcpy() and memcmp() routines in C
Message-ID: <1989Feb15.201133.16123@utzoo.uucp>
Organization: U of Toronto Zoology
References: <463@sunset.MATH.UCLA.EDU>
Date: Wed, 15 Feb 89 20:11:33 GMT

In article <463@sunset.MATH.UCLA.EDU> tony@MATH.UCLA.EDU () writes:
>Can somebody e-mail me C routines that copies (or compares) two
>structures of the same type?

Copying is fairly trivial; in fact, struct assignment is part of most
C compilers (although if he's got a real antique it may not be there).	
Just "a = b;" where a and b are structs of the same type.

Nobody is going to be able to mail you C routines that reliably and
portably compare two structures of the same type, because it can't be
done without a member-by-member comparison.  The compiler is entitled
to insert "holes" into a structure to meet alignment requirements for
following members, and there is no guarantee that those holes will
contain the same data in all structs, so a simple compare-N-bytes
function is not good enough.
-- 
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry henry@zoo.toronto.edu