COMSAT(8)						    BSD System Manager's Manual 						 COMSAT(8)

NAME

     comsat -- biff server

SYNOPSIS

     comsat

DESCRIPTION

     The comsat utility is the server process which receives reports of incoming mail and notifies users if they have requested this service.  The
     comsat utility receives messages on a datagram port associated with the ``biff'' service specification (see services(5) and inetd(8)).  The
     one line messages are of the form:

	   user@mailbox-offset[:mailbox-name]

     If the user specified is logged in to the system and the associated terminal has the owner execute bit turned on (by a ``biff y''), the
     offset is used as a seek offset into the appropriate mailbox file and the first 7 lines or 560 characters of the message are printed on the
     user's terminal.  Lines which appear to be part of the message header other than the ``From'', ``To'', ``Date'', or ``Subject'' lines are not
     included in the displayed message.

     If the user specified is logged in to the system and the associated terminal has the group execute bit turned on (by a ``biff b''), two bell
     characters (ASCII 07) are printed on the user's terminal.

     If mailbox-name omitted, standard mailbox assumed.

FILES

     /var/run/utx.active
		     to find out who is logged on and on what terminals
     /var/mail/user  standard mailbox

SEE ALSO

     biff(1), inetd(8)

HISTORY

     The comsat utility appeared in 4.2BSD.

BUGS

     The message header filtering is prone to error.  The density of the information presented is near the theoretical minimum.

     Users should be notified of mail which arrives on other machines than the one to which they are currently logged in.

     The notification should appear in a separate window so it does not mess up the screen.

BSD
								 January 21, 2010							       BSD