From: ToRA <tristan.allwood@...>
Date: 2005-10-12T00:56:57+09:00
Subject: Re: One-liner removing duplicate lines


ruby -e 'require "set" ; s = Set.new ; ARGF.each_line {|z| s.add?(z)
and puts(z) }' input > output

or even more verbose

ruby -e 'require "set" ; s = Set.new ; ARGF.each_line {|z| if s.add?(z)
then puts(z) end }' input > output

Tris