Reads a file and extracts all url's from it.

extract_urls_from_file.rb

require 'open-uri'
require 'uri'

# start off by reading the file
text = ""
File.open("whatever.txt", "r") do |f|
  f.each_line do |line|
    text << line
  end
end

# extract all links from the text
list_of_urls = text.split(/\s+/).find_all { |u| u =~ /^https?:/ }