CLOSE {syntax}*

Arguments:

  {syntax}*             Optional syntax to close.

Overview:

The CLOSE command closes an open listener. If {syntax} is not
specified, the currently active listener is closed, if any.
Otherwise {syntax} is the syntax whose listener should be
closed.  Closing may be necessary if processing becomes stuck,
or if a process other than Lisp wants to access the listening
device.

See also:

OPEN