write to all users
/etc/wall [ -g group ] [ file ]
The wall command reads a message from file
or the standard input until an end-of-file is received.
wall sends this message to all users currently
logged in. The message is preceded by a header detailing who
generated the message, the system name, and the time.
wall is used to warn all users, for example, prior to shutting
down the system.
If a group is specified using the -g option,
wall sends a message only to that group.
The sender should be root to override any protections
that users may have set on their terminal lines using
the message file could not be opened
Cannot send to ...
the user's terminal line could not be opened for writing
Only one group allowed
only one group can be selected
Unknown group group
group is not in /etc/group
wall will fail if /etc/utmp does not
exist, cannot be opened for reading, or is too large.
groups defined on this system
information about users logged onto the system
device files for console multiscreens
device files for serial ports
device files for pseudo ttys
wall is conformant with:
AT&T SVID Issue 2;
X/Open Portability Guide, Issue 3, 1990: note that the X/Open CAE Specification, Commands and Utilities, Issue 4, 1992 marks this command as
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003