WALL(1)

NAME
wall - write to all users

SYNOPSIS
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.