wall(1M)wall(1M)NAME
wall - write message to all users
SYNOPSIS
groupname] [file]
DESCRIPTION
Without arguments, the command reads a message from standard input until end-of-file. Then it sends this message to all currently logged-
in users preceded by:
If the option is specified, sends the message to all currently logged-in groupname members (as specified in preceded by:
If file is specified, reads file instead of standard input.
is typically used to warn all users prior to shutting down the system.
The sender must have appropriate privileges to override any protections the users may have invoked (see mesg(1)).
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)).
EXTERNAL INFLUENCES
International Code Set Support
Single- and multibyte character code sets are supported.
DIAGNOSTICS
The open on a user's tty file failed.
WARNINGS
The command will be WITHDRAWN from X/Open standard and may not be portable to other vendor's platforms.
AUTHOR
was developed by AT&T and HP.
FILES SEE ALSO mesg(1), write(1).
STANDARDS CONFORMANCE wall(1M)
Check Out this Related Man Page
wall(1M) System Administration Commands wall(1M)NAME
wall - write to all users
SYNOPSIS
/usr/sbin/wall [-a] [-g grpname] [filename]
DESCRIPTION
wall reads its standard input until an end-of-file. It then sends this message to all currently logged-in users preceded by:
Broadcast Message from ...
If filename is given, then the message is read in from that file. Normally, pseudo-terminals that do not correspond to rlogin sessions are
ignored. Thus, when using a window system, the message appears only on the console window. However, -a will send the message even to such
pseudo-terminals.
It is used to warn all users, typically prior to shutting down the system.
The sender must be superuser to override any protections the users may have invoked See mesg(1).
wall runs setgid() to the group ID tty, in order to have write permissions on other user's terminals. See setuid(2).
wall will detect non-printable characters before sending them to the user's terminal. Control characters will appear as a " ^ " followed
by the appropriate ASCII character; characters with the high-order bit set will appear in "meta" notation. For example, ` 03' is dis-
played as `^C' and `372' as `M-z'.
OPTIONS
The following options are supported:
-a Broadcast message to the console and pseudo-terminals.
-g grpname Broadcast to the users in a specified group only, per the group database (see group(4)).
ENVIRONMENT VARIABLES
If the LC_* variables (LC_CTYPE, LC_TIME, LC_COLLATE, LC_NUMERIC, and LC_MONETARY) are not set in the environment, the operational behav-
ior of wall for each corresponding locale category is determined by the value of the LANG environment variable. See environ(5). If LC_ALL
is set, its contents are used to override both the LANG and the other LC_* variables. If none of the above variables are set in the envi-
ronment, the "C" (U.S. style) locale determines how wall behaves.
FILES
/dev/tty*
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO mesg(1), write(1), setuid(2), attributes(5), environ(5)NOTES
wall displays ``Cannot send to ...'' when the open on a user's tty file fails.
SunOS 5.10 13 Jul 1994 wall(1M)