Path: utzoo!attcan!uunet!aplcen!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: compare strings, strcmp
Message-ID: <11620@smoke.BRL.MIL>
Date: 17 Nov 89 15:27:59 GMT
References: <4463@blake.acs.washington.edu> <11605@smoke.BRL.MIL> <548.nlhp3@oracle.nl>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 6

In article <548.nlhp3@oracle.nl> bengsig@oracle.nl (Bjorn Engsig) writes:
>|#define  StrEq( a, b )  (*(a) == *(b) && strcmp( a, b ) == 0)  /* UNSAFE */
>Is it unsafe because of side effects of evaluating a and b twice, ...

Yes, that's what the comment means.  In the file I extracted this from
there was an explanation..