Linux wall command
Linux wall command will be passed to each message mesg set to yes on-line users. When using a terminal interface as standard passed, the need to add at the end of the message EOF (usually Ctrl + D).
Access: All users.
grammar
wall [ message ]
Examples
Biography message "hi" to every user
wall hi
Broadcast news
# wall Ilove Broadcast message from root (pts/4) (Thu May 27 16:41:09 2014): Ilove