f = openListener "$:service" -- opens a listener on the local
host at the specified service port.
f = openListener "$" -- opens a listener on the local
host at the Macaulay2 port (2500).
Use openInOut f to accept an incoming connection on the listener,
returning a new input output file which serves as the connection.The return value is of type File. See File for information
about how to use such values.
