From: Stefan Lang <langstefan@...>
Date: 2005-10-06T05:39:39+09:00
Subject: Re: One-liner removing duplicate lines

On Wednesday 05 October 2005 22:34, Ryan Leavengood wrote:
> 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.

    ruby -ne 'a||={};a[$_]||=(print;1)' infile > outfile

-- 
Stefan