How to get the file extension from a url?

Question

New to ruby, how would I get the file extension from a url like:

http://www.example.com/asdf123.gif

Also, how would I format this string, in c#

Answer 1

You could use Ruby's URI class like this to get the fragment of the URI (i.e. the relative path of the file) and split it at the last occurrence of a dot (this will also work if the URL contains a query part):

require 'uri'
your_url = 'http://www.example.com/asdf123.gif'
fragment = URI.split(your_url)[5]

extension = fragment.match(/\.([\w+-]+)$/)