Using wall to broadcast messages

A superuser can use the wall command to send a message to all logged in shell users:

wall [message]

If the message is omitted from the command line, the user will receive two beeps as a prompt to enter the message. You input the message, pressing enter after each line, and when done inputting the entire message, enter end-of-file or an interrupt (typically, <EscChar-D> for end-of-file or <EscChar-C> for an interrupt).

The user of wall should be a superuser. This ensures that the user is permitted to write to all the users that are logged on. If a user who is not a superuser attempts to use wall to broadcast a message, some writes will fail and those users will not receive the message.

Users who are sent a broadcast message will receive a beep announcing the message, and a message in the form:

Broadcast Message from SWER@AQFT (ttyp0006) at 10:43:54 (EDT5EST) ...

This is the text of the message line1
This is line2

For more information on the wall command, see the wall command description in z/OS UNIX System Services Command Reference.