.TH WALL 1M .SH NAME wall \- write to all users .SH SYNOPSIS .B /etc/wall .SH DESCRIPTION .I Wall reads its standard input until an end-of-file. It then sends this message, preceded by `Broadcast Message ...', to all logged in users. .PP The sender should be super-user to override any protections the users may have invoked. .SH FILES /dev/tty? .br /etc/utmp .SH "SEE ALSO" mesg(1), write(1) .SH DIAGNOSTICS `Cannot send to ...' when the open on a user's tty file fails.