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 incom‐
     ing 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 ter‐
     minal 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 termi‐
     nal.  Lines which appear to be part of the message header other than the
     “From”, “To”, “Date”, or “Subject” lines are not included in the dis‐
     played message.

     If the user specified is logged in to the system and the associated ter‐
     minal has the group execute bit turned on (by a “biff b”), two bell char‐
     acters (ASCII \007) 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