Section: User Commands (1)
Updated: August 2013
wall - write a message to all users
or the contents of a
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
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
- -g, --group group
Limit printing message to members of group defined as a
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
ut_type data a ':' character will not get the message from
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
Linux Kernel Archive