From: "Brian D. Burns" <burns@...>
Date: 2013-01-10T18:22:38+09:00
Subject: Re: One liner for filenames

On 01/08/2013 05:04 PM, Dami叩n M. Gonz叩lez wrote:
> Peter Bailey wrote in post #1091502:
>> Hello,
>> Can someone help me to write a Ruby one-liner to remove all the files
>> except one in a list of files? I have a list of pages of an original
>> PDF. Each page has been converted to a PNG file. They're each numbered
>> with an underscore and a number at their end.
>>
>> filename_1.png
>> filename_2.png
>> filename_3.png
>> ...
>>
>> I need to basically delete all of the files except for the first one,
>> the one with the "_1" suffix at the end. Can I do that wiith a
>> one-liner?
>>
>> Thanks,
>> Peter
> 
>  Test this:
> 
> ruby -e "Dir.foreach('C:/Directory_with_png/') {|file| File.delete(file) 
> unless (file.==('.')) || (file.==('..') || (file.==('filename_1.png'))"
> 
>  Kind regards.
> 

There's certainly many ways to do this, but globing will ignore the dot
dirs, and is a bit shorter.
File.delete *Dir['*.png'].reject {|f| f =~ /_1\.png$/ }