wall
—
write a message to users
The wall
utility displays the contents of
file or, by default, its standard input, on the
terminals of all currently logged in users.
Only the super-user can write on the terminals of users who have
chosen to deny messages or are using a program which automatically denies
messages.
-g
- Send messages to users in this group. This option may be specified
multiple times, and any user in any of the specified groups will receive
the message.
A wall
command appeared in PWB UNIX.
The sender's LC_CTYPE
setting is used to determine which
characters are safe to write to a terminal, not the receiver's (which
wall
has no way of knowing).