wall -- send a message to everybody's terminal.
Wall sends a message to everybody logged in with their mesg(1)
permission set to yes. The message can be given as an argument to
wall, or it can be sent to wall's standard input. When using the
standard input from a terminal, the message should be terminated with the
EOF key (usually Control-D).
The length of the message is limited to 20 lines. For every
invocation of wall a notification will be written to syslog, with
facility LOG_USER and level LOG_INFO.
- -n
- Suppresses the normal banner printed by wall, changing it to
"Remote broadcast message". This option is only available for
root if wall is installed set-group-id, and is used by
rpc.walld(8).
Wall ignores the TZ variable - the time printed in the banner is
based on the system's local time.
Miquel van Smoorenburg, miquels@cistron.nl