1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)comsat.8 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd January 21, 2010 32.Dt COMSAT 8 33.Os 34.Sh NAME 35.Nm comsat 36.Nd biff server 37.Sh SYNOPSIS 38.Nm 39.Sh DESCRIPTION 40The 41.Nm 42utility is the server process which receives reports of incoming mail 43and notifies users if they have requested this service. 44The 45.Nm 46utility receives messages on a datagram port associated with the 47.Dq biff 48service 49specification (see 50.Xr services 5 51and 52.Xr inetd 8 ) . 53The one line messages are of the form: 54.Pp 55.D1 Ar user Ns @ Ns Ar mailbox Ns - Ns Ar offset Ns Op : Ns Ar mailbox-name 56.Pp 57If the 58.Ar user 59specified is logged in to the system and the associated terminal has 60the owner execute bit turned on (by a 61.Dq Nm biff Cm y ) , 62the 63.Ar offset 64is used as a seek offset into the appropriate mailbox file and 65the first 7 lines or 560 characters of the message are printed 66on the user's terminal. 67Lines which appear to be part of 68the message header other than the 69.Dq Li From , 70.Dq Li \&To , 71.Dq Li Date , 72or 73.Dq Li Subject 74lines are not included in the displayed message. 75.Pp 76If the 77.Ar user 78specified is logged in to the system and the associated terminal has 79the group execute bit turned on (by a 80.Dq Nm biff Cm b ) , 81two bell characters 82.Tn ( ASCII 83\\007) are printed on the user's terminal. 84.Pp 85If 86.Ar mailbox-name 87omitted, standard mailbox assumed. 88.Sh FILES 89.Bl -tag -width ".Pa /var/mail/user" -compact 90.It Pa /var/run/utx.active 91to find out who is logged on and on what terminals 92.It Pa /var/mail/user 93standard mailbox 94.El 95.Sh SEE ALSO 96.Xr biff 1 , 97.Xr inetd 8 98.Sh HISTORY 99The 100.Nm 101utility appeared in 102.Bx 4.2 . 103.Sh BUGS 104The message header filtering is prone to error. 105The density of the information presented is near the theoretical minimum. 106.Pp 107Users should be notified of mail which arrives on other 108machines than the one to which they are currently logged in. 109.Pp 110The notification should appear in a separate window so it 111does not mess up the screen. 112