Package rwall

Client for sending messages to a host's logged in users

ftp://ftp.linux.org.uk/pub/linux/Networking/netkit/

The rwall command sends a message to all of the users logged into a
specified host. Actually, your machine's rwall client sends the
message to the rwall daemon running on the specified host, and the
rwall daemon relays the message to all of the users logged in to that
host.

Install rwall if you'd like the ability to send messages to users
logged in to a specified host machine.

General Commands
Command Description
rwall send a message to users logged on a host