# File raggle, line 5273
    def Engine::get_exec_url(url, last_modified = nil)
      ret = [nil, nil]

      # work with a copy of the url
      cmd = url.dup

      # strip 'exec:' prefix from URL
      cmd.gsub!(/^[^:]+?:/, '') if cmd =~ /^[^:]+?:/

      # no cache, just get the result
      begin 
        pipe = IO::popen(cmd, 'r')
        ret = [pipe.read, nil]
        pipe.close
      rescue
        raise "Couldn't read exec URL: #$!"
      end

      # return URL content and last-modified header
      ret
    end