wall(ADM)


wall -- write to all users

Syntax

/etc/wall [ -g group ] [ file ]

Description

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 mesg(C).

Diagnostics


file??
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

Limitations

wall will fail if /etc/utmp does not exist, cannot be opened for reading, or is too large.

Files


/etc/group
groups defined on this system

/etc/utmp
information about users logged onto the system

/dev/tty[01][0-9]
device files for console multiscreens

/dev/tty[12][a-hA-H]
device files for serial ports

/dev/ttyp*
device files for pseudo ttys

See also

group(F), mesg(C), write(C)

Standards conformance

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Issue 3, 1990: note that the X/Open CAE Specification, Commands and Utilities, Issue 4, 1992 marks this command as withdrawn.


© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 03 June 2005