Provided by: xscreensaver-data_5.08-0ubuntu3_i386 bug


        sonar - display a sonar scope


        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]


        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 millisec-
        onds respectively.
        Alternately, it can run a simulation that doesn't involve hosts.


        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
                hostname    Ping the given host.
                A.B.C.D     Ping the given IP address.
                subnet      Ping  the  local  class  C  subnet (the nearest 255
                subnet/NN   Ping a different-sized  local  subnet:  e.g.,  sub-
                            net/28  would  ping  a 4-bit subnet (the nearest 15
                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
                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
                              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.
                Keep the display stationary instead  of  very  slowly  wobbling
                back and forth.
        -no-dns 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.
        -fps    Display the current frame rate, polygon count, and CPU load.


        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.)
        X(1), xscreensaver(1), ping(8)


        Copyright (C) 2000-2008 by Jamie Zawinski <>
        Copyright (C) 1998 by Stephen Martin. <>
        Permission to use, copy, modify, distribute, and sell this software and
        its  documentation  for any purpose is hereby granted without fee, pro-
        vided that the above copyright notice appear in  all  copies  and  that
        both  that  copyright  notice and this permission notice appear in sup-
        porting documentation.  No representations are made about the suitabil-
        ity  of  this software for any purpose.  It is provided "as is" without
        express or implied warranty.


        Stephen Martin <>, 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.