A system administrator may need to send messages to the terminal of every user or a specified user on all the machines over a network. This recipe is a guide on how to perform this task.
wall
is a command that is used to write messages on the terminals of all logged in users. It can be used to convey messages to all logged in users on a server or multiple access machines. Sending messages to all users may not be useful at all times. Terminals are treated as devices in a Linux system and hence, these opened terminals will have a corresponding device node file at /dev/pts/
. Writing data to a specific device will display messages on the corresponding terminal.