# `letsencrypt.plugins.util`

Plugin utilities.

`letsencrypt.plugins.util.``already_listening`(port, renewer=False)

  Check if a process is already listening on the port.

  If so, also tell the user via a display notification.

  Warning

  On some operating systems, this function can only usefully be run as root.

  Parameters: | port (int) – The TCP port in question.
  Returns: | True or False.