gistfile1.rb

    foo = {}
    basenames = ActionController::Routing::Routes.named_routes.routes.keys
    basenames.each {|name| foo[name] = false}
    Dir.glob(File.join(RAILS_ROOT, '/app', '**', '*.rb')).each do |file|
      data = File.read(file)
      basenames.each do |basename|
        reg =  Regexp.new(basename.to_s+"_(?=url|path)")
        if reg.match data
          foo[basename] = true
        end
      end
    end
    unused = foo.reject{|k, v| v == true}