Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!haven!adm!xadmx!rbj@nav.icst.nbs.gov
From: rbj@nav.icst.nbs.gov (Root Boy Jim)
Newsgroups: comp.unix.questions
Subject: sorting and reversing lines of a file
Message-ID: <18706@adm.BRL.MIL>
Date: 14 Mar 89 17:03:40 GMT
Sender: news@adm.BRL.MIL
Lines: 23

? From: Francois-Michel Lang <lang@pearl.prc.unisys.com>

? I need utilities to do two things:
? (1) reverse the order of lines in a file
?     but leave the lines themselves intact.
?     The Unix utility does just the opposite of this.

You don't want to do this, but it does work!

sed -e '1{;h;d;}' -e '$!{;G;h;d;}' -e '$G'

Well, up to a point anyway. An `ls -l /etc | wc -l' produces 140 lines
on our system. Piping the ls to the sed command produced only about 70
lines, giving a total of 4000 characters. That seems to be the limit.

Don't forget to quote the `!' if using csh.  The semicolons are an
undocumented feature.  An awk script would be a better way to do this.
Tail -r seems to be the best buggestion unless you are reversing
really BIG files. In that case you probably do want to write a C
program. There's just no escaping the buffering problem.

	Catman Rshd <rbj@nav.icst.nbs.gov>
	Author of "The Daemonic Versions"