who@ 1 user commands djbwares
who@ prints the list of active users on a remote host.
`who@` host

## Description

`who@` uses tcpclient 1 to connect to TCP port 11 on host and prints any data that it receives. It uses delcr 1 and cat 1 to remove CR (\015) and convert unprintable characters to a visible format.

If host is not supplied, `who@` connects to the local host.

TCP port 11 is the well-known port for the Systat service. Some computers respond to connections on this port with a list of active users. For example, they may be running `tcpserver -R -H -l0 0 11 who` using tcpserver 1.

## History

`who@` was originally part of Daniel J. Bernstein's ucspi-tcp toolset in 1999.

## Author

Original code and documentation by Daniel J. Bernstein. Documentation modernizations by Jonathan de Boyne Pollard.