wall(1m) - write to all users

[mountaing]

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.  Nor-
       mally,  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 sys-
       tem.


       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 permis-
       sions 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,  `\003'  is  displayed  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 behavior
       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 environ-
       ment, 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                  system/core-os               |
       +-----------------------------------------------------------+

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 5.11                        23 Feb 2015                         wall(1M)