wall

WALL(1)                          User Commands                         WALL(1)

NAME
       wall - write a message to all users

SYNOPSIS
       wall [-n] [-t timeout] [-g group] [message | file]

DESCRIPTION
       wall displays a message, or the contents of a file, or otherwise its
       standard input, on the terminals of all currently logged in users. The
       command will wrap lines that are longer than 79 characters. Short lines
       are whitespace padded to have 79 characters. The command will always
       put a carriage return and new line at the end of each line.

       Only the superuser can write on the terminals of users who have chosen
       to deny messages or are using a program which automatically denies
       messages.

       Reading from a file is refused when the invoker is not superuser and
       the program is set-user-ID or set-group-ID.

OPTIONS
       -n, --nobanner
           Suppress the banner.

       -t, --timeout timeout
           Abandon the write attempt to the terminals after timeout seconds.
           This timeout must be a positive integer. The default value is 300
           seconds, which is a legacy from the time when people ran terminals
           over modem lines.

       -g, --group group
           Limit printing message to members of group defined as a group
           argument. The argument can be group name or GID.

       -V, --version
           Display version information and exit.

       -h, --help
           Display help text and exit.

NOTES
       Some sessions, such as wdm(1x), that have in the beginning of utmp(5)
       ut_type data a ':' character will not get the message from wall. This
       is done to avoid write errors.

HISTORY
       A wall command appeared in Version 7 AT&T UNIX.

SEE ALSO
       mesg(1), talk(1), write(1), shutdown(8)

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/karelzak/util-linux/issues.

AVAILABILITY
       The wall command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.37.2                 2021-06-02                           WALL(1)