comsat
listens on a datagram port associated with the
biff
service specification (see
services(4tcp))
for one line messages of the form
user@mailbox-offset
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 printed when displaying the message.