From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-09-08T00:18:21+09:00
Subject: Re: regular expression match and exclude

On Sun, Sep 7, 2008 at 3:09 PM, Azalar --- <pteale@gmail.com> wrote:
> I am parsing a web page full of image links that also contain links to
> the thumbnails for those images.
>
> Here is my test data..
>
> galleries/image1.jpg
> galleries/image1thumb.jpg
> galleries/image2.jpg
> galleries/image2thumb.jpg
> galleries/image3.jpg
> galleries/image3thumb.jpg
>
> If i use this expression..
> /galleries.*(?=thumb).*jpg/
>
> The results are just those lines containing the word thumb.
>
> What I want to do is inverse this though and return only return that
> DONT contain the word thumb.

If you have all the links in an array, I would do the opposite: match
the ones that contain
thumb, rejecting those from the array

irb(main):001:0> links = %w{galleries/image1.jpg
galleries/image1thumb.jpg galleries/image2.jpg
galleries/image2thumb.jpg galleries/image3.jpg
galleries/image3thumb.jpg}
=> ["galleries/image1.jpg", "galleries/image1thumb.jpg",
"galleries/image2.jpg", "galleries/image2thumb.jpg",
"galleries/image3.jpg", "galleries/image3thumb.jpg"]

irb(main):007:0> links.reject {|l| l =~ /thumb/}
=> ["galleries/image1.jpg", "galleries/image2.jpg", "galleries/image3.jpg"]

You can as specific as you need for the regexp:

irb(main):008:0> links.reject {|l| l =~ /galleries\/.*thumb.*jpg/}
=> ["galleries/image1.jpg", "galleries/image2.jpg", "galleries/image3.jpg"]


Hope this helps,

Jesus.