$home/manuals/unix_v8/8/wall

WALL(8)                     System Manager's Manual                    WALL(8)

NAME
       wall - write to all users

SYNOPSIS
       /etc/wall

DESCRIPTION
       Wall reads its standard input until an end-of-file.  It then sends this
       message, preceded by ‘Broadcast Message ...', to all logged in users.

       The  sender  should be super-user to override any protections the users
       may have invoked.

FILES
       /dev/tty?
       /etc/utmp

SEE ALSO
       mesg(1), write(1)

DIAGNOSTICS
       ‘Cannot send to ...' when the open on a user's tty file fails.

                                                                       WALL(8)