xscreensaver-command(1)       XScreenSaver manual      xscreensaver-command(1)



NAME
       xscreensaver-command - control a running xscreensaver process

SYNOPSIS
       xscreensaver-command  [-display  host:display.screen]  [-help | -demo |
       -prefs | -activate | -deactivate | -cycle | -next | -prev | -select n |
       -exit | -restart | -lock | -version | -time | -watch]

DESCRIPTION
       The   xscreensaver-command  program  controls  a  running  xscreensaver
       process by sending it client-messages.

       xscreensaver(1) has a client-server model: the xscreensaver process  is
       a  daemon  that runs in the background; it is controlled by other fore-
       ground programs such as xscreensaver-command and xscreensaver-demo(1).

       This program, xscreensaver-command, is  a  command-line-oriented  tool;
       the xscreensaver-demo(1).  program is a graphical tool.

OPTIONS
       xscreensaver-command accepts the following command-line options:

       -help   Prints a brief summary of command-line options.

       -demo   This  just  launches the xscreensaver-demo(1) program, in which
               one can experiment with the various graphics  hacks  available,
               and edit parameters.

       -demo number
               When  the  -demo option is followed by an integer, it instructs
               the xscreensaver daemon to run that hack, and wait for the user
               to click the mouse before deactivating (i.e., mouse motion does
               not deactivate.)  This  is  the  mechanism  by  which  xscreen-
               saver-demo(1)  communicates  with  the  xscreensaver(1) daemon.
               (The first hack in the list is numbered 1, not 0.)

       -prefs  Like the no-argument form of -demo, but  brings  up  that  pro-
               gram's Preferences panel by default.

       -activate
               Tell  xscreensaver  to  turn on immediately (that is, blank the
               screen, as if the user had been idle  for  long  enough.)   The
               screensaver will deactivate as soon as there is any user activ-
               ity, as usual.

               It is useful to run this from a menu; you may wish to run it as
               sleep 5 ; xscreensaver-command -activate
               to be sure that you have time to take your hand off  the  mouse
               before  the  screensaver  comes on.  (Because if you jiggle the
               mouse, xscreensaver will notice, and deactivate.)

       -deactivate
               This tells xscreensaver to pretend that  there  has  just  been
               user  activity.   This  means that if the screensaver is active
               (the screen is blanked),  then  this  command  will  cause  the
               screen  to  un-blank  as  if  there  had been keyboard or mouse
               activity.  If the screen is locked, then  the  password  dialog
               will  pop  up  first,  as usual.  If the screen is not blanked,
               then this simulated user activity will re-start  the  countdown
               (so, issuing the -deactivate command periodically is one way to
               prevent the screen from blanking.)

       -cycle  If the screensaver is active (the screen is blanked), then stop
               the current graphics demo and run a new one (chosen randomly.)

       -next   This  is like either -activate or -cycle, depending on which is
               more appropriate, except that the graphics hack  that  will  be
               run  is  the next one in the list, instead of a randomly-chosen
               one.  In other words, repeatedly executing -next will cause the
               xscreensaver process to invoke each graphics demo sequentially.
               (Though using the -demo option is probably  an  easier  way  to
               accomplish that.)

       -prev   This is like -next, but cycles in the other direction.

       -select number
               Like  -activate, but runs the Nth element in the list of hacks.
               By knowing what is in the programs list, and in what order, you
               can  use  this  to  activate  the screensaver with a particular
               graphics demo.  (The first element in the list is  numbered  1,
               not 0.)

       -exit   Causes  the xscreensaver process to exit gracefully.  This does
               nothing if the display is currently locked.

               Warning: never use kill -9 with xscreensaver while the  screen-
               saver  is  active.  If you are using a virtual root window man-
               ager, that can leave things in an inconsistent state,  and  you
               may need to restart your window manager to repair the damage.

       -lock   Tells the running xscreensaver process to lock the screen imme-
               diately.  This is like -activate, but forces locking  as  well,
               even  if  locking is not the default (that is, even if xscreen-
               saver's lock resource is false, and  even  if  the  lockTimeout
               resource is non-zero.)

               Note  that locking doesn't work unless the xscreensaver process
               is running as you.  See xscreensaver(1) for details.

       -version
               Prints the version of xscreensaver that is currently running on
               the  display: that is, the actual version number of the running
               xscreensaver background process, rather than the version number
               of   xscreensaver-command.   (To  see  the  version  number  of
               xscreensaver-command itself, use the -help option.)

       -time   Prints the time at which  the  screensaver  last  activated  or
               deactivated  (roughly,  how long the user has been idle or non-
               idle: but not quite, since it only tells you  when  the  screen
               became blanked or un-blanked.)

       -restart
               Causes  the  screensaver  process to exit and then restart with
               the same command line arguments as last  time.   You  shouldn't
               really  need  to  do  this, since xscreensaver notices when the
               .xscreensaver file has changed and re-reads it as needed.

       -watch  Prints a line each time the screensaver changes state: when the
               screen  blanks,  locks,  unblanks,  or when the running hack is
               changed.  This option never returns; it is intended for use  by
               shell  scripts  that  want  to react to the screensaver in some
               way.  An example of its output would be:
               BLANK Fri Nov  5 01:57:22 1999
               RUN 34
               RUN 79
               RUN 16
               LOCK Fri Nov  5 01:57:22 1999
               RUN 76
               RUN 12
               UNBLANK Fri Nov  5 02:05:59 1999
               The above shows the screensaver activating, running three  dif-
               ferent  hacks,  then  locking (perhaps because the lock-timeout
               went off) then unblanking (because the user became active,  and
               typed  the correct password.)  The hack numbers are their index
               in the `programs' list (starting with 1,  not  0,  as  for  the
               -select command.)

               For  example, suppose you want to run a program that turns down
               the volume on your machine when the screen blanks, and turns it
               back  up  when the screen un-blanks.  You could do that by run-
               ning a Perl program like the following in the background.   The
               following  program  tracks the output of the -watch command and
               reacts accordingly:
               #!/usr/bin/perl

               my $blanked = 0;
               open (IN, "xscreensaver-command -watch |");
               while (<IN>) {
                   if (m/^(BLANK|LOCK)/) {
                       if (!$blanked) {
                           system "sound-off";
                           $blanked = 1;
                       }
                   } elsif (m/^UNBLANK/) {
                       system "sound-on";
                       $blanked = 0;
                   }
               }
               Note that LOCK might come either with or  without  a  preceding
               BLANK  (depending  on whether the lock-timeout is non-zero), so
               the above program keeps track of both of them.

STOPPING GRAPHICS
       If xscreensaver is running, but you want  it  to  stop  running  screen
       hacks (e.g., if you are logged in remotely, and you want the console to
       remain locked but just be black, with no  graphics  processes  running)
       you  can  accomplish that by simply powering down the monitor remotely.
       In a minute or so, xscreensaver will notice that the  monitor  is  off,
       and will stop running screen hacks.  You can power off the monitor like
       so:
       xset dpms force off
       See the xset(1) manual for more info.

       You can also use xscreensaver-demo(1) to make the  monitor  power  down
       after a few hours, meaning that xscreensaver will run graphics until it
       has been idle for the length of time you specified; and after that, the
       monitor will power off, and screen hacks will stop being run.

DIAGNOSTICS
       If an error occurs while communicating with the xscreensaver daemon, or
       if the daemon reports an error, a diagnostic message will be printed to
       stderr,  and  xscreensaver-command will exit with a non-zero value.  If
       the command is accepted, an indication of this will be printed to  std-
       out, and the exit value will be zero.

ENVIRONMENT
       DISPLAY to get the host and display number of the screen whose saver is
               to be manipulated.

       PATH    to find the executable to restart (for the  -restart  command).
               Note  that this variable is consulted in the environment of the
               xscreensaver process, not the xscreensaver-command process.

UPGRADES
       The latest version of xscreensaver(1) and related tools can  always  be
       found at http://www.jwz.org/xscreensaver/

SEE ALSO
       X(1), xscreensaver(1), xscreensaver-demo(1), xset(1)

COPYRIGHT
       Copyright  (C)  1992-2013  by Jamie Zawinski.  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 war-
       ranty.

AUTHOR
       Jamie Zawinski <jwz@jwz.org>, 13-aug-1992.

       Please let me know if you find any bugs or make any improvements.



X Version 11                  5.30 (11-Sep-2014)       xscreensaver-command(1)
