NAME

wall − write to all users

SYNOPSIS

/etc/wall

DESCRIPTION

The wall command 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 must be super-user to override any protections the users may have invoked [see mesg(1)].

FILES

/dev/tty∗

SEE ALSO

mesg(1), write(1). 

DIAGNOSTICS

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

\*U  —  Version 1.0