From: Ryan Leavengood <leavengood@...>
Date: 2005-10-06T05:34:18+09:00
Subject: Re: One-liner removing duplicate lines

On 10/5/05, Ryan Leavengood <leavengood@gmail.com> wrote:
>
> I tried creating a version that mimics the Perl one (because Ruby also
> has the -n option), but in the end this seemed easier (and much more
> readable):
>
> ruby -e "puts IO.readlines(ARGV[0]).uniq" infile > outfile
>
> So you are right about using uniq.

Just for sake of comparison, here is the more "Perl-like" version:

ruby -ne "s||={};s[$_]||print;s[$_]=1" infile > outfile

Maybe some Ruby golfers can shorten it some more, but since Ruby lacks
some of the more terse (and obfuscating) features of Perl, it may not
be possible.

Ryan