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 to all currently logged in users preceded by “Broadcast Message from ...”.  It is used to warn all users, typically prior to shutting down the system. 

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

FILES

/dev/tty∗

SEE ALSO

mesg(1), write(1). 

DIAGNOSTICS

“Cannot send to ...” when the open on a user’s tty file fails. 

May 16, 1980