who@ hostwho@ connects to TCP port 11 (Systat) on host and prints any data it receives. It removes CR (\015) and converts unprintable characters to a visible format.
If host is not supplied, who@ connects to the local host.
Some computers respond to port 11 with a list of active users. For example, they may be running
tcpserver -RHl0 0 11 whousing tcpserver.