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.

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* Not currently supported under MachTen