freebsd man page for wall

WALL(1) 						    BSD General Commands Manual 						   WALL(1)

NAME
     wall -- write a message to users

SYNOPSIS
     wall [-g group] [file]

DESCRIPTION
     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.

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

HISTORY
     A wall command appeared in PWB UNIX.

BUGS
     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).

BSD
								 February 24, 2012							       BSD