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From: gvr@cs.brown.edu (George V. Reilly)
Newsgroups: comp.lang.c
Subject: Re: Efficient STRing CoMPares?
Message-ID: <68822@brunix.UUCP>
Date: 17 Mar 91 01:38:02 GMT
References: <1991Mar15.142821@mars.mpr.ca>
Sender: news@brunix.UUCP
Reply-To: gvr@cs.brown.edu (George V. Reilly)
Organization: Brown University, Dept. of Computer Science
Lines: 23

In article <1991Mar15.142821@mars.mpr.ca> stone@mars.mpr.ca (Darren Stone) writes:
% 
% Does anyone know if there's a better (!?) way to compare
% strings than with strcmp()?
% 
% I'm looking for any speed advantage I can get!

If you're comparing strings for equality, you could use the
following macro:

#define STREQ(a,b) (*(a) == *(b) && (*(a) == '\0' || strcmp((a)+1,(b)+1) == 0))

which only calls strcmp() if the two strings agree in the first
character and if they're not zero-length strings.  Thus, for most
string comparisons, strcmp will not be called.  Unless the
implementors of your libraries really botched it, strcmp()
should already be extremely efficient.

You should be able to work out STRLT, STRLE, STRNE, STRGE, and STRGT
(if you need them) based on the above example.
________________
George V. Reilly   `Toad of Toad Hall'	gvr@cs.brown.edu   +1 (401) 863-7684
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