Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.jpl.nasa.gov (Larry Wall)
Newsgroups: comp.unix.questions
Subject: Re: Searching the output of last
Keywords: last awk sed perl C whatever
Message-ID: <1991Apr30.175521.17233@jpl-devvax.jpl.nasa.gov>
Date: 30 Apr 91 17:55:21 GMT
References: <1991Apr29.040325.1822@athena.mit.edu> <1991Apr29.043041.20454@casbah.acns.nwu.edu> <1991Apr29.072206.5621@jpl-devvax.jpl.nasa.gov> <130922@uunet.UU.NET>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 23

In article <130922@uunet.UU.NET> rbj@uunet.UU.NET (Root Boy Jim) writes:
: The first file contains login records for today only.
: The second is cumulative for the entire month.
: We upgraded the OS yesterday, so you can extrapolate
: that it would take about an hour alone to run last
: on a whole month's statistics.
: 
: >last|perl -pe '$_ x=/(..:..)...(.*)/&&"'$1'"ge$1&&"'$1'"lt$2'
: >
: >That's gonna be tough for Randal to beat...  :-)
: 
: I just ran it with args 12:34 and 23:45. Here's the timing:
: 137.510u 88.580s 4:58.87 75% 0+0k 212+7io 0pf+0w
: 
: Five minutes for one day. Two and 1/2 hours for the entire month.
: 
: OK, so we're not a typical site :-)

Oh, good grief.  I wasn't optimizing for speed, but brevity (obscurity?).
By all means, read the file directly if you want speed.  There's More
Than One Way To Do It.

Larry