def cmd_nlst(param)
      send_unauthorised and return unless logged_in?
      send_response "150 Opening ASCII mode data connection for file list"

      @driver.dir_contents(build_path(param)) do |files|
        send_outofband_data(files.map(&:name))
      end
    end
def cmd_nlst(param)
      send_unauthorised and return unless logged_in?
      send_response "150 Opening ASCII mode data connection for file list"

      @driver.dir_contents(build_path(param)) do |files|
        send_outofband_data(files.map(&:name))
      end
    end
return a listing of the current directory, one per line, each line
 separated by the standard FTP EOL sequence. The listing is returned
 to the client over a data socket.