[\-team-a-count \fIint\fP]
[\-team-b-count \fIint\fP]
[\-no\-dns]
+[\-no\-times]
[\-debug]
.SH DESCRIPTION
The \fIsonar\fP program displays a sonar scope on the computer's screen.
.B \-no\-dns
Do not attempt to resolve IP addresses to hostnames.
.TP 8
+.B \-no\-times
+Do not display ping times beneath the host names.
+.TP 8
.B \-team-a-name \fIstring\fP
In simulation mode, the name of team A.
.TP 8
.B teamBCount \fIint\fP
See option \-teamBCount, above. Default value is 4.
.SH NOTES
-In order to use the ping sensor, this program must be installed as
-setuid root, so that it can create an ICMP socket. Root privileges
-are disavowed shortly after startup (just after connecting to the
-X server and reading the resource database) so this is \fIbelieved\fP
-to be a safe thing to do, but it is usually recommended that you
-have as few setuid programs around as possible, on general principles.
+In order to use the ping sensor on most systems, this program must be
+installed as setuid root, so that it can create an ICMP RAW socket.
+Root privileges are disavowed shortly after startup (just after
+connecting to the X server and reading the resource database) so this
+is \fIbelieved\fP to be a safe thing to do, but it is usually
+recommended that you have as few setuid programs around as possible,
+on general principles.
.EX
-chown root.root sonar
+chown root:root sonar
chmod u+s sonar
.EE
+It is not necessary to make it setuid on MacOS systems, because on
+those systems, unprivileged programs can ping by using ICMP DGRAM
+sockets instead of ICMP RAW.
+
+In ping-mode, the display is a logarithmic scale, calibrated so that the
+three rings represent ping times of approximately 2.5, 70 and 2,000
+milliseconds respectively.
+
+This means that if any the hosts you are pinging take longer than 2
+seconds to respond, they won't show up; and if you are pinging several
+hosts with very fast response times, they will all appear close to the
+center of the screen (making their names hard to read.)
.SH SEE ALSO
.BR X (1),
.BR xscreensaver (1),
Stephen Martin <smartin@canada.com>, 3-nov-98.
Thanks to Tom Kelly for suggesting a modular approach to the sensor
-amoung other things.
+among other things.
Thomas Bahls <thommy@cs.tu-berlin.de> hacked the "ttl" option, 12-jul-98.