Provided by: xscreensaver-data-extra_5.15-3+deb7u1ubuntu0.1_amd64 
NAME
sonar - display a sonar scope
SYNOPSIS
sonar [-ping hosts-or-subnets] [-ping-timeout int] [-delay usecs] [-speed ratio] [-sweep-size ratio]
[-font-size points] [-team-a-name string] [-team-b-name string] [-team-a-count int] [-team-b-count int]
[-no-dns] [-no-times] [-no-wobble] [-debug] [-fps]
DESCRIPTION
This draws a sonar screen that pings (get it?) the hosts on your local network, and plots their distance
(response time) from you. The three rings represent ping times of approximately 2.5, 70 and 2,000
milliseconds respectively.
Alternately, it can run a simulation that doesn't involve hosts.
OPTIONS
sonar understands the following options:
-ping hosts-or-subnets
The list of things to ping, separated by commas or spaces. Elements of this list may be:
simulation Run in simulation mode instead of pinging real hosts.
hostname Ping the given host.
A.B.C.D Ping the given IP address.
subnet Ping the local class C subnet (the nearest 255 addresses).
subnet/NN Ping a different-sized local subnet: e.g., subnet/28 would ping a 4-bit subnet (the
nearest 15 addresses).
A.B.C.D/NN Ping an arbitrary other subnet. The IP address specifies the base address, and the
part after the slash is how wide the subnet is. Typical values are /24 (for 255
addresses) and /28 (for 15 addresses).
filename Ping the hosts listed in the given file. This file can be in the format used by
/etc/hosts, or it can be any file that has host names as the first or second element
on each line. If you use ssh, try this:
sonar -ping $HOME/.ssh/known_hosts
-ping-timeout int
The amount of time in milliseconds the program will wait for an answer to a ping.
-delay int
Delay between frames, in microseconds. Default 20000.
-speed ratio
Less than 1 for slower, greater than 1 for faster. Default 1.
-sweep-size ratio
How big the glowing sweep area should be. Default 0.3.
-font-size points
How large the text should be. Default 10 points.
-no-wobble
Keep the display stationary instead of very slowly wobbling back and forth.
-no-dns Do not attempt to resolve IP addresses to hostnames.
-no-times
Do not display ping times beneath the host names.
-team-a-name string
In simulation mode, the name of team A.
-team-b-name string
In simulation mode, the name of team B.
-team-a-count int
In simulation mode, the number of bogies on team A.
-team-b-count int
In simulation mode, the number of bogies on team B.
-fps Display the current frame rate, polygon count, and CPU load.
NOTES
On most Unix systems, this program must be installed as setuid root in order to ping hosts. This is
because root privileges are needed to create an ICMP RAW socket. Privileges are disavowed shortly after
startup (just after connecting to the X server) so this is believed to be safe:
chown root:root sonar
chmod u+s sonar
It is not necessary to make it setuid on MacOS systems, because on MacOS, 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.)
SEE ALSO
X(1), xscreensaver(1), ping(8)
COPYRIGHT
Copyright © 2000-2008 by Jamie Zawinski <jwz@jwz.org> Copyright © 1998 by Stephen Martin. <smartin@canada.com> Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. No representations are made about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
AUTHORS
Stephen Martin <smartin@canada.com>, 3-nov-1998. Subnet support, etc. added by Jamie Zawinski, 17-Jul-2000. Rewritten using OpenGL instead of X11 by Jamie Zawinski, 12-Aug-2008.