Checks a site for links that lead to 404 pages

Gemfile

source "http://rubygems.org"
gem 'anemone'

main.rb

require "rubygems"
require "bundler/setup"
require "anemone"

Anemone.crawl("http://example.com") do |anemone|
  anemone.on_every_page do |page|      
    if page.code == 404
      puts 'oops! ' + page.url
    end
  end
end