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From: wagner@iaoobelix.UUCP
Newsgroups: comp.sources.d
Subject: Fastest `grep'?? Really? - (nf)
Message-ID: <7200003@iaoobelix.UUCP>
Date: Sun, 21-Jun-87 11:35:00 EDT
Article-I.D.: iaoobeli.7200003
Posted: Sun Jun 21 11:35:00 1987
Date-Received: Fri, 26-Jun-87 03:35:51 EDT
Lines: 33
Nf-ID: #N:iaoobelix:7200003:000:1457
Nf-From: iaoobelix!wagner    Jun 21 16:35:00 1987


A few weeks ago, the "fastest grep around" was posted thru comp.sources. Well,
reading this announcement I was really interested in the preformance figures
of this nice program. So I just moved it over to a Sun 3/260 (SunOS 3.2) and
compiled it as it came with 'notes'.

Ahemm! Well!	**SURPRISE**

The results I obtained from just little playing around with this reportedly
fastest grep program were a bit :-) :-) disappointing. Below you find the
figures I got from doing a
	time grep "[0-9][a-z] [a-z]" /usr/man/cat2/* > /dev/null
with several grep versions. I say several versions (not just two) because
there are three of them:
	(a) the standard /bin/grep coming with UNIX,
	(b) the grep from comp.sources, and
	(c) the grep from an older posting of Ozan S. Yigit (utzoo!yetti!oz)
	    coming with the author's own version of the regexp package
	    (here, it is called re_exp).

Ok, here are the timing figures:
	(a) time: 6.7u + 0.9s = 60% of 0:12
	(b) time: 29.7u + 1.3s = 89% of 0:34
	(c) time: 6.5u + 1.0s = 70% of 0:10
Remember: It is a Sun 3/260, and I am the only user; nobody's distracting my
machine from grepping thru /usr/man/cat2...

Is there anybody out there who knows why some people called the program (a)
the "fastest grep around"?? Apparently, it is the factor four (in average)
slower even than the standard `grep'...

Juergen Wagner,		     (USENET) ...seismo!unido!iaoobel!wagner
("Gandalf")			 Fraunhofer Institute IAO, Stut7=EENV