wall

This command is used to communicate with all users. It stands for "write all". The command can be used by issuing the wall command followed by the message and concluded with Ctrl+D.

Example:

wall

Please observe all security regulations.

Ctrl+D

The message will be broadcast to all users online.

Here is an example from a user using wall. First you type the command wall and then follow it with the message for all users. The broadcast will indicate which user sent the message.

mike@ub:~$ wall

hello

Broadcast Message from mike@ub

(/dev/pts/0) at 5:12 ...

hello

You can check to see if wall is installed with:

rpm -q wall

wall has a security history so many admins do not install it.