Provided by: xscreensaver-data-extra_5.08-0ubuntu5_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
       milliseconds 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.,
                           subnet/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 © 2000-2008 by Jamie Zawinski <>
       Copyright © 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,
       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.


       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.