sonarSection: XScreenSaver manual (6)
Updated: 5.04 (13-Nov-2007)
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NAMEsonar - display a sonar scope
SYNOPSISsonar [-ping hosts-or-subnets] [-background color] [-sweep-color color] [-low-color color] [-scope-color color] [-grid-color color] [-text-color color] [-ttl integer] [-font font] [-ping-timeout int] [-team-a-name string] [-team-b-name string] [-team-a-count int] [-team-b-count int] [-no-dns] [-no-times] [-debug]
DESCRIPTIONThe sonar program displays a sonar scope on the computer's screen. This scope polls a sensor as the sweep goes around the scope and displays what it finds as bogies on the screen. The program is designed to support different modes representing different types of sensors. Currently the only implemented sensors are a simulator, and a network ping function that pings hosts and plots the results on the scope.
OPTIONSsonar understands the following options:
- -background Color
- The background Color of the screen not covered by the scope.
- -sweep-color Color
- The color of the brightest part of the sweep.
- -scope-color Color
- The color of the circular part of the scope.
- -grid-color Color
- The color to the grid lines overlaying the scope.
- -text-color Color
- The color of the text identifying bogies on the scope.
- -ttl integer
- "Time to live": visible time of a Bogie. Try values between 10 (very short) and 100.
- -font font
- The font used to display text on the scope. Default "fixed".
- -ping-timeout int
- The amount of time in milliseconds the program will wait for an answer to a ping.
- -ping hosts-or-subnets
The list of things to ping, separated by commas or spaces.
Elements of this list may be:
- to run in simulation mode, instead of pinging real hosts (this is the default if the program is not installed setuid);
- to ping the given host;
- to ping the given IP address;
- to ping the local class C subnet (the nearest 255 addresses);
- to ping a different-sized local subnet: e.g., subnet/28 would ping a 4-bit subnet (the nearest 15 addresses);
- to 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.)
to 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 element on each line. If you use ssh, try this:
sonar -ping $HOME/.ssh/known_hosts
- Do not attempt to resolve IP addresses to hostnames.
- 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.
RESOURCESConfiguration of the targets to ping is best done by setting X Resources.
- background (Color)
- See option -background, above; default value is black.
- sweepColor (Color)
- See option -sweep-color, above; default value is #00ff00.
- scopeColor (Color)
- See option -scope-color, above; default value is #003300.
- gridColor (Color)
- See option -grid-color, above; default value is #00aa00.
- textColor (Color)
- See option -text-color, above; default value is #ffff00.
- ttl (integer)
- See option -ttl, above; default value is 90 or one sweep.
- ping (string)
- See option -ping, above. If set to default, it will ping the contents of /etc/hosts if possible, otherwise, will run in simulation-mode.
- font (font)
- See option -font, above; default value is fixed.
- pingTimeout (Integer)
- See option -pingtimeout, above; default value is 3000.
- teamAName string
- See option -team-a-name, above. Default value is F18.
- teamBName string
- See option -teamBName, above. Default value is MIG.
- teamACount int
- See option -teamACount, above. Default value is 4.
- teamBCount int
- See option -teamBCount, above. Default value is 4.
NOTESIn 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 believed 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.
chown root:root sonar chmod u+s sonar
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.)
SEE ALSOX(1), xscreensaver(1), ping(8)
COPYRIGHTCopyright © 1998 by Stephen Martin. <email@example.com> Copyright © 2000-2004 by Jamie Zawinski <firstname.lastname@example.org>
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.
AUTHORSStephen Martin <email@example.com>, 3-nov-98.
Thanks to Tom Kelly for suggesting a modular approach to the sensor among other things.
Thomas Bahls <firstname.lastname@example.org> hacked the "ttl" option, 12-jul-98.
Better subnet support and command-line processing by Jamie Zawinski, 17-Jul-00.