wall - write message to all users
/usr/sbin/wall [-ggroupname] [file]
/usr/sbin/cwall [-ggroupname] [file]
Without arguments, the wall command reads a message from standard
input until end-of-file. Then it sends this message to all currently
logged-in users preceded by:
Broadcast Message from ...
If the -ggroupname option is specified, wall sends the message to all
currently logged-in groupname members (as specified in /etc/group)
Broadcast Message from ... to group groupname
If file is specified, wall reads file instead of standard input.
wall is typically used to warn all users prior to shutting down the
The sender must have appropriate privileges to override any
protections the users may have invoked (see mesg(1)).
wall has timing delays, and takes at least 30 seconds to complete.
You must have appropriate privileges to override any protections users
may have invoked (see mesg(1)).
International Code Set Support
Single- and multibyte character code sets are supported.
Cannot send to ...
The open on a user's tty file failed.
The wall command will be WITHDRAWN from X/Open standard and may not be
portable to other vendor's platforms.
wall was developed by AT&T and HP.
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000
wall: SVID2, SVID3, XPG2, XPG3
Hewlett-Packard Company - 2 - HP-UX Release 11i: November 2000