NAME

       wall - write a message to all users

SYNOPSIS

       wall [-n] [-t timeout] [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 suid
       or sgid.

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.

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

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

NOTES

       Some sessions, such as wdm, 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.

SEE ALSO

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

HISTORY

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

AVAILABILITY

       The  wall  command  is  part  of the util-linux package and is available from Linux Kernel
       Archive ⟨ftp://ftp.kernel.org/pub/linux/utils/util-linux/⟩.