Provided by: xscreensaver-gl_6.02+dfsg1-2ubuntu2_amd64 bug

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 IPv4 address.

               subnet      Ping the local subnet.  On systems where we can  determine  the  local
                           network mask, we use that; otherwise, we assume Class C (254 hosts).

               subnet/NN   Ping  a  different-sized  local  subnet:  e.g., subnet/28 would ping a
                           4-bit subnet (the nearest 14 addresses).   On  systems  where  we  can
                           determine the local network mask, we always use that.

               A.B.C.D/NN  Ping  an  arbitrary other IPv4 subnet.  The address specifies the base
                           address, and the part after the slash  is  how  wide  the  subnet  is.
                           Typical values are /24 (for 254 addresses) and /28 (for 14 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.

       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.)

INSTALLATION

       For  this  program  to  be able to ping other hosts, it must have the ability to open ICMP
       sockets, which is usually an action that requires additional privileges.

       If your system has setcap(8) then this permission can be added with

            setcap cap_net_raw=p sonar

       Otherwise, the program must be setuid  root  in  order  to  ping  hosts.   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 use setcap or setuid on macOS systems, as unprivileged programs can
       ping by using ICMP DGRAM sockets instead of ICMP RAW.

BUGS

       Does not support IPv6.

SEE ALSO

       X(1), xscreensaver(1), ping(8), ping6(8)

COPYRIGHT

       Copyright © 2000-2021 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.