.TH wall "" "" Command
.PC "Send a message to all logged-in users"
\fB/etc/wall\fR
.PP
.B wall
types a message to every user
currently logged into the \*(CO system, with the exception
of the sender.
It can be used to inform users of information
of general interest; for example, that man
has landed on the moon, or that the
system is going down in 15 minutes.
.PP
.B wall
reads the message to be broadcast from the standard input
until end of file.
When it sends the message,
it prefaces it with
the herald ``Broadcast message ...'',
which includes an audible warning.
Only the superuser should invoke
.B /etc/wall
(to override access protections
of the target terminals).
.SH Files
\fB/etc/utmp\fR \(em Current users file
.br
.B /dev/tty*
.SH "See Also"
.Xr "commands," commands
.Xr "msg," msg.c
.Xr "who," who
.Xr "write" write.c
.SH Diagnostics
The message ``Cannot send to
.I user
on \fIttyname\fR'' indicates that
.B wall
cannot write to the given
.IR user .
