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From: jfh@rpp386.cactus.org (John F Haugh II)
Newsgroups: comp.bugs.sys5
Subject: Re: SVR3 Utilities (Was: Re: small bug in who(1) of SVR3)
Message-ID: <18948@rpp386.cactus.org>
Date: 15 Jan 91 15:27:18 GMT
References: <1991Jan13.004843.18650@zoo.toronto.edu> <18899@rpp386.cactus.org> <1991Jan14.202053.20054@zoo.toronto.edu> <BW2^?6-@uzi-9mm.fulcrum.bt.co.uk>
Reply-To: jfh@rpp386.cactus.org (John F Haugh II)
Organization: Lone Star Cafe and BBS Service
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In article <BW2^?6-@uzi-9mm.fulcrum.bt.co.uk> igb@fulcrum.bt.co.uk (Ian G Batten) writes:
>I don't doubt it.  I had to use ``sum'' in a small utility and was
>shocked at its performance.  When I rewrote it as a function --- rather
>than running it down a pipe --- and removed some obvious infelicitudes
>it ran about three times faster.  That with, oh, half an hour's effort.

Well, I do doubt it.  Here is a collection of examples.  It should be
obvious that the pipe loses out over the single C command.  Of course,
on a system with a load average <1, waste is just fine.

% timex who -q
jfh jfh jfh root 
# users=4
execution complete

real	         0.18
user	         0.02
sys	         0.08
% timex users
jfh root
execution complete

real	         0.19
user	         0.00
sys	         0.05
% timex /bin/sh -c 'who | cut -d" " -f1 | sort -u | tr \\012 " " ; echo ""'
jfh root 
execution complete

real	         0.79
user	         0.02
sys	         0.22
-- 
John F. Haugh II                             UUCP: ...!cs.utexas.edu!rpp386!jfh
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