From: "Simon Kröger" <SimonKroeger@...>
Date: 2005-10-06T06:05:29+09:00
Subject: Re: One-liner removing duplicate lines

Stefan Lang wrote:

> 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

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

cheers

Simon