URLs finden, Ruby

#!/usr/bin/env ruby
while gets
    while /\b((https?|ftp|file):\/\/|(www|ftp)\.)[\-A-Z0-9+&@#\/%?=~_|\$!,.;:]*[A-Z0-9+&@#\/%=~_|\$]/i
        puts $&
        $_.sub! /\b((https?|ftp|file):\/\/|(www|ftp)\.)[\-A-Z0-9+&@#\/%?=~_|\$!,.;:]*[A-Z0-9+&@#\/%=~_|\$]/i, ''
    end
end