who@

## Name

who@ — prints the list of active users on a remote host.

## Synopsis

`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.