Linux "wall" Command Line Options and Examples
write a message to all users
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.
Usage:
wall [-n] [-t timeout] [-g group] [message | file]
Command Line Options:
-n
Suppress the banner.
wall -n ...
-t
Abandon the write attempt to the terminals after timeout seconds. This timeout must be a positiveinteger. The default value is 300 seconds, which is a legacy from the time when people ran terminalsover modem lines.
wall -t ...
-g
Limit printing message to members of group defined as a group argument. The argument can be group nameor GID.
wall -g ...
-V
Display version information and exit.
wall -V ...
-h
Display help text and exit.NOTESSome sessions, such as wdm, that have in the beginning of utmp(5) ut_type data a ':' character will not getthe message from wall. This is done to avoid write errors.
wall -h ...