freebsd-nq/libexec/comsat/comsat.8

.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)comsat.8	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd July 9, 2002
.Dt COMSAT 8
.Os
.Sh NAME
.Nm comsat
.Nd biff server
.Sh SYNOPSIS
.Nm
.Sh DESCRIPTION
The
.Nm
utility is the server process which receives reports of incoming mail
and notifies users if they have requested this service.
The
.Nm
utility receives messages on a datagram port associated with the
.Dq biff
service
specification (see
.Xr services 5
and
.Xr inetd 8 ) .
The one line messages are of the form:
.Pp
.D1 Ar user Ns @ Ns Ar mailbox Ns - Ns Ar offset Ns Op : Ns Ar mailbox-name
.Pp
If the
.Ar user
specified is logged in to the system and the associated terminal has
the owner execute bit turned on (by a
.Dq Nm biff Cm y ) ,
the
.Ar 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
.Dq Li From ,
.Dq Li \&To ,
.Dq Li Date ,
or
.Dq Li Subject
lines are not included in the displayed message.
.Pp
If the
.Ar user
specified is logged in to the system and the associated terminal has
the group execute bit turned on (by a
.Dq Nm biff Cm b ) ,
two bell characters
.Tn ( ASCII
\\007) are printed on the user's terminal.
.Pp
If
.Ar mailbox-name
omitted, standard mailbox assumed.
.Sh FILES
.Bl -tag -width ".Pa /var/mail/user" -compact
.It Pa /var/run/utmp
to find out who is logged on and on what terminals
.It Pa /var/mail/user
standard mailbox
.El
.Sh SEE ALSO
.Xr biff 1 ,
.Xr inetd 8
.Sh HISTORY
The
.Nm
utility appeared in
.Bx 4.2 .
.Sh BUGS
The message header filtering is prone to error.
The density of the information presented is near the theoretical minimum.
.Pp
Users should be notified of mail which arrives on other
machines than the one to which they are currently logged in.
.Pp
The notification should appear in a separate window so it
does not mess up the screen.