wall - write a message to all users
] [-t timeout
] [-g group
displays a message
, or the contents of a file
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.
- -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.
Some sessions, such as wdm, that have in the beginning of utmp(5)
data a ':' character will not get the message from wall
. This is done
to avoid write errors.
command appeared in Version 7 AT&T UNIX.
The wall command is part of the util-linux package and is available from