+may be a hostname, an IPv4 address in dotted-quad format, or an IPv6
+address in hex-and-colons format (this last obviously requires selecting
+a different delimeter character). Additionally,
+.I local-port
+may be a string of the form
+.BI ? file
+to get the kernel to allocate an unused port number, and then write the
+port to the named
+.IR file .
+Exactly two