1.\" Copyright (c) 1983, 1991 The Regents of the University of California. 2.\" 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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)comsat.8 6.5 (Berkeley) 3/16/91 33.\" 34.Dd March 16, 1991 35.Dt COMSAT 8 36.Os BSD 4.2 37.Sh NAME 38.Nm comsat 39.Nd biff server 40.Sh SYNOPSIS 41.Nm comsat 42.Sh DESCRIPTION 43.Nm Comsat 44is the server process which receives reports of incoming mail 45and notifies users if they have requested this service. 46.Nm Comsat 47receives messages on a datagram port associated with the 48.Dq biff 49service 50specification (see 51.Xr services 5 52and 53.Xr inetd 8 ) . 54The one line messages are of the form: 55.Pp 56.Dl user@mailbox-offset 57.Pp 58If the 59.Em user 60specified is logged in to the system and the associated terminal has 61the owner execute bit turned on (by a 62.Dq Li biff y ) , 63the 64.Em offset 65is used as a seek offset into the appropriate mailbox file and 66the first 7 lines or 560 characters of the message are printed 67on the user's terminal. Lines which appear to be part of 68the message header other than the 69.Dq From , 70.Dq \&To , 71.Dq Date , 72or 73.Dq Subject 74lines are not included in the displayed message. 75.Sh FILES 76.Bl -tag -width /var/run/utmp -compact 77.It Pa /var/run/utmp 78to find out who's logged on and on what terminals 79.El 80.Sh SEE ALSO 81.Xr biff 1 , 82.Xr inetd 8 83.Sh BUGS 84The message header filtering is prone to error. 85The density of the information presented is near the theoretical minimum. 86.Pp 87Users should be notified of mail which arrives on other 88machines than the one to which they are currently logged in. 89.Pp 90The notification should appear in a separate window so it 91does not mess up the screen. 92.Sh HISTORY 93The 94.Nm 95command appeared in 96.Bx 4.2 . 97