Gracefully shuts down socket connection to client.
Mnemonic:
GoodBYE.
Syntax:
BYE [pn]
pn: ZY port number to close (0 = TCP port 5240,
1 = TCP port 5241)
Return values:
Success:
BYE 1, pn, Closing Connection
Failure:
BYE 0, err_msg
pn: TCP port number, 5240 or 5241
err_msg: Should the command fail, this value will
be an error message string, explaining the cause of failure.
Failure modes include providing a ZY port number greater than
1 or less than 0 (the ZY currently only supports two TCP ports),
and providing a non-numeric port number.
Remarks:
The ZY supports two TCP ports, at 5240 and 5241. Only one socket
may connect to each port at one time. The ZY lists these as port
0 and port 1, respectively. BYE will close the specified port (0
or 1) if the parameter is given, or it will default to the port over
which the command was issued, if the parameter is not given. For
example, if a client connected to port 1 issues a BYE command with
no parameters, BYE assumes port 1 is to be closed. A client
connected to port 0 may close port 1 and vice-versa. Upon receipt
of this command, the ZY closes the connection to the client
computer and immediately waits for a new one. The following
idiosyncrasies should be noted about this command:
Though the port number is given as `0' or `1' when the
command is issued, the acknowledged command string returned
to the client lists the port as the actual TCP port number
instead.
The ZY should but currently does not trap port numbers
outside the supported range of 0-1 as errors.
Both of these items will be addressed in future releases.
