Provided by: xscreensaver_5.15-2ubuntu1_i386 bug


       xscreensaver - extensible screen saver framework, plus locking


       xscreensaver  [-display  host:display.screen]  [-verbose]  [-no-splash]
       [-no-capture-stderr] [-log filename]


       The xscreensaver program waits until the keyboard and mouse  have  been
       idle  for a period, and then runs a graphics demo chosen at random.  It
       turns off as soon as there is any mouse or keyboard activity.

       This program can lock your terminal in order  to  prevent  others  from
       using  it,  though  its  default mode of operation is merely to display
       pretty pictures on your screen when it is not in use.

       It also provides configuration and control  of  your  monitor's  power-
       saving features.


       For the impatient, try this:
       xscreensaver &
       The  xscreensaver-demo(1)  program  pops  up a dialog box that lets you
       configure the screen saver, and experiment  with  the  various  display

       Note  that  xscreensaver  has  a  client-server model: the xscreensaver
       program is a daemon that runs in the background; it  is  controlled  by
       the   foreground   xscreensaver-demo(1)   and   xscreensaver-command(1)


       The easiest  way  to  configure  xscreensaver  is  to  simply  run  the
       xscreensaver-demo(1)  program, and change the settings through the GUI.
       The rest of this manual page describes lower  level  ways  of  changing

       I'll repeat that because it's important:

           The  easy way to configure xscreensaver is to run the xscreensaver-
           demo(1) program.  You shouldn't need  to  know  any  of  the  stuff
           described  in  this  manual  unless  you are trying to do something
           tricky, like customize xscreensaver for site-wide use or something.

       Options to  xscreensaver  are  stored  in  one  of  two  places:  in  a
       .xscreensaver  file  in  your  home  directory;  or  in  the X resource
       database.  If the .xscreensaver file exists, it overrides any  settings
       in the resource database.

       The  syntax  of  the  .xscreensaver  file  is  similar  to  that of the
       .Xdefaults file; for example,  to  set  the  timeout  paramter  in  the
       .xscreensaver file, you would write the following:
       timeout: 5
       whereas, in the .Xdefaults file, you would write
       xscreensaver.timeout: 5
       If you change a setting in the .xscreensaver file while xscreensaver is
       already running, it will notice this, and reload the file.   (The  file
       will  be  reloaded  the  next  time the screen saver needs to take some
       action, such as blanking or unblanking the screen,  or  picking  a  new
       graphics mode.)

       If  you  change  a  setting in your X resource database, or if you want
       xscreensaver to notice your changes immediately  instead  of  the  next
       time  it  wakes  up, then you will need to reload your .Xdefaults file,
       and then tell the running xscreensaver process to restart itself,  like
       xrdb < ~/.Xdefaults
       xscreensaver-command -restart
       If  you  want  to set the system-wide defaults, then make your edits to
       the xscreensaver app-defaults file, which should  have  been  installed
       when  xscreensaver  itself  was  installed.  The app-defaults file will
       usually be named /usr/lib/X11/app-defaults/XScreenSaver, but  different
       systems   might   keep   it   in   a   different  place  (for  example,
       /usr/openwin/lib/app-defaults/XScreenSaver on Solaris.)

       When settings are changed in the Preferences dialog box (see above) the
       current  settings  will  be  written  to  the .xscreensaver file.  (The
       .Xdefaults file and the app-defaults file  will  never  be  written  by
       xscreensaver itself.)


       xscreensaver  also  accepts  a few command-line options, mostly for use
       when debugging: for normal operation, you should configure  things  via
       the ~/.xscreensaver file.

       -display host:display.screen
               The  X  display  to  use.   For displays with multiple screens,
               XScreenSaver  will  manage   all   screens   on   the   display

               Same as setting the verbose resource to true: print diagnostics
               on stderr and on the xscreensaver window.

               Do  not  redirect  the  stdout  and  stderr  streams   to   the
               xscreensaver  window  itself.  If xscreensaver is crashing, you
               might need to do this in order to see the error message.

       -log filename
               This is exactly the same as redirecting stdout  and  stderr  to
               the  given  file  (for  append).  This is useful when reporting


       When it is time to activate the screensaver, a full-screen black window
       is  created  on  each screen of the display.  Each window is created in
       such a way that, to any subsequently-created programs, it  will  appear
       to  be  a  "virtual  root"  window.  Because of this, any program which
       draws on the root window (and which understands virtual roots)  can  be
       used  as  a screensaver.  The various graphics demos are, in fact, just
       standalone programs that know how to draw on the provided window.

       When the  user  becomes  active  again,  the  screensaver  windows  are
       unmapped,  and  the  running  subprocesses  are  killed by sending them
       SIGTERM.  This is  also  how  the  subprocesses  are  killed  when  the
       screensaver decides that it's time to run a different demo: the old one
       is killed and a new one is launched.

       You  can  control  a  running  screensaver   process   by   using   the
       xscreensaver-command(1) program (which see.)


       Modern  X  servers  contain  support to power down the monitor after an
       idle period.  If the monitor has powered down, then  xscreensaver  will
       notice  this  (after  a few minutes), and will not waste CPU by drawing
       graphics demos on a black screen.  An attempt  will  also  be  made  to
       explicitly  power  the  monitor  back  up  as  soon as user activity is

       The ~/.xscreensaver file controls the configuration of  your  display's
       power  management  settings:  if  you  have used xset(1) to change your
       power  management  settings,  then  xscreensaver  will  override  those
       changes  with  the  values  specified  in  ~/.xscreensaver (or with its
       built-in defaults, if there is no ~/.xscreensaver file yet.)

       To change your power management settings, run xscreensaver-demo(1)  and
       change  the  various timeouts through the user interface.  Alternately,
       you can edit the ~/.xscreensaver file directly.

       If   the   power   management   section   is   grayed   out   in    the
       xscreensaver-demo(1)  window,   then that means that your X server does
       not support the XDPMS extension, and  so  control  over  the  monitor's
       power state is not available.

       If  you're  using  a  laptop,  don't  be surprised if changing the DPMS
       settings has no effect: many laptops have monitor power-saving behavior
       built  in at a very low level that is invisible to Unix and X.  On such
       systems, you can typically  adjust  the  power-saving  delays  only  by
       changing settings in the BIOS in some hardware-specific way.

       If  DPMS  seems  not  to  be working with XFree86, make sure the "DPMS"
       option is set in your /etc/X11/XF86Config file.  See the  XF86Config(5)
       manual for details.


       For  the better part of a decade, GNOME shipped xscreensaver as-is, and
       everything just worked out of the box.  In 2005, however, they  decided
       to  re-invent  the  wheel  and  ship  their  own  replacement  for  the
       xscreensaver daemon called "gnome-screensaver", rather  than  improving
       xscreensaver  and  contributing  their  changes back.  As a result, the
       "gnome-screensaver" program is insecure, bug-ridden, and  missing  many
       features of xscreensaver.  You shouldn't use it.

       To replace gnome-screensaver with xscreensaver:

           1: Turn off gnome-screensaver.
              Open  the "System / Preferences / Screensaver" panel and uncheck
              both boxes.

           2: Stop gnome-screensaver from launching at login.
              Run the command:

              gconftool-2 --type boolean -s \
              /apps/gnome_settings_daemon/screensaver/start_screensaver \

              Or, just uninstall the "gnome-screensaver" package entirely.

           3: Launch xscreensaver at login.
              Open the "System / Preferences / Sessions  /  Startup  Programs"
              panel.  Click "Add" and type "xscreensaver".

           4: Tell Preferences to use the xscreensaver configurator.
              Edit                  /usr/share/applications/gnome-screensaver-
              preferences.desktop and change the Exec= line to say

           5: Make "System / Quit / Lock Screen" use xscreensaver.
              Run the command:
              sudo ln -sf /usr/bin/xscreensaver-command \


       Like GNOME, KDE also decided to invent their own screen saver framework
       from  scratch instead of simply using xscreensaver.  To replace the KDE
       screen saver with xscreensaver, do the following:

           1: Turn off KDE's screen saver.
              Open the "Control Center" and select the "Appearance & Themes  /
              Screensaver" page.  Un-check "Start Automatically".

           2: Find your Autostart directory.
              Open the "System Administration / Paths" page, and see what your
              "Autostart   path"   is   set   to:   it   will   probably    be
              ~/.kde/Autostart/ or something similar.

           3: Make xscreensaver be an Autostart program.
              Create  a  .desktop  file  in  your  autostart  directory called
              xscreensaver.desktop that contains the following five lines:

              [Desktop Entry]

           4: Make the various "lock session" buttons call xscreensaver.
              The file you want to replace next  has  moved  around  over  the
              years. It might be called /usr/libexec/kde4/kscreenlocker, or it
              might be called "kdesktop_lock" or "krunner_lock", and it  might
              be  in /usr/lib/kde4/libexec/ or in /usr/kde/3.5/bin/ or even in
              /usr/bin/, depending on  the  distro  and  phase  of  the  moon.
              Replace the contents of that file with these two lines:

              xscreensaver-command -lock

              Make sure the file is executable (chmod a+x).

       Now   use   xscreensaver   normally,   controlling  it  via  the  usual
       xscreensaver-demo(1) and xscreensaver-command(1) mechanisms.


       You can  run  xscreensaver  from  your  gdm(1)  session,  so  that  the
       screensaver  will run even when nobody is logged in on the console.  To
       do this, run gdmconfig(1) and on the Background page, type the  command
       "xscreensaver  -nosplash" into the Background Program field.  That will
       cause gdm to run xscreensaver while nobody is logged in, and kill it as
       soon  as  someone  does log in.  (The user will then be responsible for
       starting xscreensaver on their own, if they want.)

       Another  way  to  accomplish  the  same  thing  is  to  edit  the  file
       /etc/X11/gdm/gdm.conf to include:
       BackgroundProgram=xscreensaver -nosplash
       In this situation, the xscreensaver process will probably be running as
       user gdm instead of root.  You can  configure  the  settings  for  this
       nobody-logged-in   state   (timeouts,   DPMS,   etc.)  by  editing  the
       ~gdm/.xscreensaver file.

       To get gdm to run the BackgroundProgram, you may need to switch it from
       the "Graphical Greeter" to the "Standard Greeter".

       It  is safe to run xscreensaver as root (as xdm or gdm may do.)  If run
       as root, xscreensaver changes its  effective  user  and  group  ids  to
       something  safe  (like  "nobody")  before connecting to the X server or
       launching user-specified programs.

       An unfortunate side effect of this (important) security  precaution  is
       that it may conflict with cookie-based authentication.

       If  you  get "connection refused" errors when running xscreensaver from
       gdm, then this probably means that you  have  xauth(1)  or  some  other
       security mechanism turned on.  For information on the X server's access
       control mechanisms, see the man pages for X(1), Xsecurity(1), xauth(1),
       and xhost(1).


       Bugs?   There  are  no bugs.  Ok, well, maybe.  If you find one, please
       let me know. explains how to
       construct the most useful bug reports.

       Locking and root logins
           In  order for it to be safe for xscreensaver to be launched by xdm,
           certain precautions had to be taken, among them  that  xscreensaver
           never  runs  as root.  In particular, if it is launched as root (as
           xdm is likely to do), xscreensaver will disavow its privileges, and
           switch itself to a safe user id (such as nobody.)

           An  implication  of  this  is  that  if  you  log in as root on the
           console, xscreensaver will refuse to lock the  screen  (because  it
           can't  tell  the  difference  between  root  being logged in on the
           console, and a normal user being  logged  in  on  the  console  but
           xscreensaver having been launched by the xdm(1) Xsetup file.)

           The  solution to this is simple: you shouldn't be logging in on the
           console as root in the  first  place!   (What,  are  you  crazy  or

           Proper  Unix  hygiene  dictates that you should log in as yourself,
           and su(1) to root as necessary.  People who spend their day  logged
           in as root are just begging for disaster.

       XAUTH and XDM
           For  xscreensaver  to  work  when  launched  by  xdm(1)  or gdm(1),
           programs running on the local machine as user "nobody" must be able
           to  connect  to  the  X server.  This means that if you want to run
           xscreensaver on the console while nobody is logged in, you may need
           to disable cookie-based access control (and allow all users who can
           log in to the local machine to connect to the display.)

           You should be sure that this is an acceptable thing to do  in  your
           environment  before  doing it.  See the "Using GDM" section, above,
           for more details.

           If you get an error message at startup like "couldn't get  password
           of  user" then this probably means that you're on a system in which
           the getpwent(3) library routine can only  be  effectively  used  by
           root.   If this is the case, then xscreensaver must be installed as
           setuid to root in order for locking to work.  Care has  been  taken
           to make this a safe thing to do.

           It  also may mean that your system uses shadow passwords instead of
           the standard getpwent(3) interface; in that case, you may  need  to
           change some options with configure and recompile.

           If  you  change your password after xscreensaver has been launched,
           it will continue using your old password to unlock the screen until
           xscreensaver  is  restarted.   On  some systems, it may accept both
           your old and new passwords.  So, after you  change  your  password,
           you'll have to do
           xscreensaver-command -restart
           to make xscreensaver notice.

       PAM Passwords
           If your system uses PAM (Pluggable Authentication Modules), then in
           order for xscreensaver to use PAM properly, PAM must be told  about
           xscreensaver.   The xscreensaver installation process should update
           the   PAM    data    (on    Linux,    by    creating    the    file
           /etc/pam.d/xscreensaver  for  you,  and  on Solaris, by telling you
           what lines to add to the /etc/pam.conf file.)

           If the PAM configuration files do not know about xscreensaver, then
           you  might be in a situation where xscreensaver will refuse to ever
           unlock the screen.

           This is a design flaw in PAM (there is no way for a client to  tell
           the  difference  between PAM responding "I have never heard of your
           module", and responding, "you typed the wrong password".)   As  far
           as  I  can  tell, there is no way for xscreensaver to automatically
           work around this, or detect the problem in advance, so if you  have
           PAM, make sure it is configured correctly!

       Machine Load
           Although  this  program  "nices"  the  subprocesses that it starts,
           graphics-intensive subprograms can still overload  the  machine  by
           causing  the  X  server  process  itself  (which is not "niced") to
           consume many cycles.  Care  has  been  taken  in  all  the  modules
           shipped  with  xscreensaver to sleep periodically, and not run full
           tilt, so as not to cause appreciable load.

           However, if you are running the OpenGL-based  screen  savers  on  a
           machine  that does not have a video card with 3D acceleration, they
           will make your machine slow, despite nice(1).

           Your options are: don't use the OpenGL display modes;  or,  collect
           the  spare  change hidden under the cushions of your couch, and use
           it to buy a video card manufactured after 1998.  (It  doesn't  even
           need  to be fast 3D hardware: the problem will be fixed if there is
           any 3D hardware at all.)

       XFree86's Magic Keystrokes
           The XFree86 X server traps certain magic keystrokes  before  client
           programs   ever   see   them.    Two   that   are   of   note   are
           Ctrl+Alt+Backspace,  which  causes  the  X  server  to  exit;   and
           Ctrl+Alt+Fn,  which  switches  virtual consoles.  The X server will
           respond to these keystrokes even if  xscreensaver  has  the  screen
           locked.   Depending  on  your  setup,  you  might  consider  this a

           Unfortunately, there is no way for xscreensaver itself to  override
           the   interpretation  of  these  keys.   If  you  want  to  disable
           Ctrl+Alt+Backspace globally, you need to set the  DontZap  flag  in
           your  /etc/X11/XF86Config  file.  To globally disable VT switching,
           you can set the DontVTSwitch flag.  See  the  XF86Config(5)  manual
           for details.


       These  are  the  X  resources  use  by  the  xscreensaver program.  You
       probably  won't  need  to  change  these  manually  (that's  what   the
       xscreensaver-demo(1) program is for).

       timeout (class Time)
               The  screensaver  will  activate  (blank  the screen) after the
               keyboard and mouse  have  been  idle  for  this  many  minutes.
               Default 10 minutes.

       cycle (class Time)
               After  the  screensaver has been running for this many minutes,
               the currently running graphics-hack sub-process will be  killed
               (with  SIGTERM), and a new one started.  If this is 0, then the
               graphics hack will never be changed: only  one  demo  will  run
               until the screensaver is deactivated by user activity.  Default
               10 minutes.

       lock (class Boolean)
               Enable locking: before the screensaver will turn off,  it  will
               require you to type the password of the logged-in user (really,
               the person who ran xscreensaver), or the root password.  (Note:
               this  doesn't  work  if  the  screensaver is launched by xdm(1)
               because it can't know the user-id of the logged-in  user.   See
               the "Using XDM(1)" section, below.

       lockTimeout (class Time)
               If  locking  is enabled, this controls the length of the "grace
               period" between when the screensaver activates,  and  when  the
               screen becomes locked.  For example, if this is 5, and -timeout
               is 10, then after 10 minutes, the screen would blank.  If there
               was  user activity at 12 minutes, no password would be required
               to un-blank the screen.  But, if there was user activity at  15
               minutes   or   later  (that  is,  -lock-timeout  minutes  after
               activation) then a password would be required.  The default  is
               0,  meaning that if locking is enabled, then a password will be
               required as soon as the screen blanks.

       passwdTimeout (class Time)
               If the screen is locked, then this  is  how  many  seconds  the
               password  dialog box should be left on the screen before giving
               up (default 30 seconds.)  This should not be too large:  the  X
               server is grabbed for the duration that the password dialog box
               is up (for security purposes) and leaving  the  server  grabbed
               for too long can cause problems.

       dpmsEnabled (class Boolean)
               Whether power management is enabled.

       dpmsStandby (class Time)
               If power management is enabled, how long until the monitor goes
               solid black.

       dpmsSuspend (class Time)
               If power management is enabled, how long until the monitor goes
               into power-saving mode.

       dpmsOff (class Time)
               If  power  management  is  enabled,  how long until the monitor
               powers down completely.  Note that these settings will have  no
               effect  unless  both  the  X  server  and  the display hardware
               support power management; not all do.  See the Power Management
               section, below, for more information.

       dpmsQuickOff (class Boolean)
               If  mode  is  blank  and  this is true, then the screen will be
               powered down immediately upon  blanking,  regardless  of  other
               power-management settings.

       visualID (class VisualID)
               Specify which X visual to use by default.  (Note carefully that
               this resource is called visualID, not merely visual; if you set
               the visual resource instead, things will malfunction in obscure
               ways for obscure reasons.)

               Legal values for the VisualID resource are:

               default Use the screen's default visual (the visual of the root
                       window.)  This is the default.

               best    Use  the  visual which supports the most colors.  Note,
                       however, that the visual with the most colors might  be
                       a  TrueColor  visual,  which  does not support colormap
                       animation.   Some  programs   have   more   interesting
                       behavior  when  run  on  PseudoColor  visuals  than  on

               mono    Use a monochrome visual, if there is one.

               gray    Use a grayscale or staticgray visual, if there  is  one
                       and  it  has  more  than  one  plane (that is, it's not

               color   Use the best of the color visuals, if there are any.

               GL      Use the  visual  that  is  best  for  OpenGL  programs.
                       (OpenGL  programs  have somewhat different requirements
                       than other X programs.)

               class   where  class  is  one   of   StaticGray,   StaticColor,
                       TrueColor,   GrayScale,  PseudoColor,  or  DirectColor.
                       Selects the deepest visual of the given class.

               number  where number (decimal  or  hex)  is  interpreted  as  a
                       visual  id  number,  as  reported  by  the  xdpyinfo(1)
                       program; in this way you can have  finer  control  over
                       exactly  which visual gets used, for example, to select
                       a shallower one than would otherwise have been chosen.

               Note that this option specifies only the  default  visual  that
               will  be  used: the visual used may be overridden on a program-
               by-program  basis.   See  the  description  of   the   programs
               resource, below.

       installColormap (class Boolean)
               On  PseudoColor  (8-bit)  displays,  install a private colormap
               while the screensaver is active, so that the graphics hacks can
               get  as  many  colors as possible.  This is the default.  (This
               only applies when the screen's default visual  is  being  used,
               since    non-default    visuals   get   their   own   colormaps
               automatically.)  This can also  be  overridden  on  a  per-hack
               basis:  see the discussion of the default-n name in the section
               about the programs resource.

               This does nothing if you have a TrueColor  (16-bit  or  deeper)

       verbose (class Boolean)
               Whether to print diagnostics.  Default false.

       timestamp (class Boolean)
               Whether  to  print  the  time  of  day  along  with  any  other
               diagnostic messages.  Default true.

       splash (class Boolean)
               Whether to display a splash screen at startup.  Default true.

       splashDuration (class Time)
               How long the splash screen should  remain  visible;  default  5

       helpURL (class URL)
               The  splash screen has a Help button on it.  When you press it,
               it will display  the  web  page  indicated  here  in  your  web

       loadURL (class LoadURL)
               This  is  the  shell  command  used to load a URL into your web
               browser.    The   default   setting   will   load    it    into
               Mozilla/Netscape  if  it  is  already  running, otherwise, will
               launch a new browser looking at the helpURL.

       demoCommand (class DemoCommand)
               This is the shell command run  when  the  Demo  button  on  the
               splash window is pressed.  It defaults to xscreensaver-demo(1).

       prefsCommand (class PrefsCommand)
               This  is  the  shell  command  run when the Prefs button on the
               splash    window    is     pressed.      It     defaults     to
               xscreensaver-demo -prefs.

       newLoginCommand (class NewLoginCommand)
               If  set,  this  is  the shell command that is run when the "New
               Login" button is pressed on the unlock dialog box, in order  to
               create  a  new desktop session without logging out the user who
               has locked the screen.  Typically this will be some variant  of
               gdmflexiserver(1) or kdmctl(1).

       nice (class Nice)
               The  sub-processes  created  by xscreensaver will be "niced" to
               this level, so that they are given lower  priority  than  other
               processes   on   the   system,  and  don't  increase  the  load
               unnecessarily.  The default is 10.  (Higher numbers mean  lower
               priority; see nice(1) for details.)

       fade (class Boolean)
               If  this  is  true,  then  when  the screensaver activates, the
               current contents of the screen will fade to  black  instead  of
               simply  winking  out.   This  only works on certain systems.  A
               fade will also be done when switching graphics hacks (when  the
               cycle timer expires.)  Default: true.

       unfade (class Boolean)
               If  this  is  true,  then when the screensaver deactivates, the
               original contents of the screen will fade in from black instead
               of  appearing immediately.  This only works on certain systems,
               and if fade is true as well.  Default false.

       fadeSeconds (class Time)
               If fade is true, this is how long the fade will be  in  seconds
               (default 3 seconds.)

       fadeTicks (class Integer)
               If  fade  is true, this is how many times a second the colormap
               will be  changed  to  effect  a  fade.   Higher  numbers  yield
               smoother  fades,  but  may  make the fades take longer than the
               specified fadeSeconds if your server isn't fast enough to  keep
               up.  Default 20.

       captureStderr (class Boolean)
               Whether  xscreensaver  should  redirect  its  stdout and stderr
               streams to the window itself.  Since its nature is to take over
               the screen, you would not normally see error messages generated
               by xscreensaver or the sub-programs it runs; this resource will
               cause  the  output  of all relevant programs to be drawn on the
               screensaver window itself, as well  as  being  written  to  the
               controlling   terminal   of  the  screensaver  driver  process.
               Default true.

       ignoreUninstalledPrograms (class Boolean)
               There may be programs in the list that are not installed on the
               system,  yet  are  marked  as "enabled."  If this preference is
               true, then such programs will simply  be  ignored.   If  false,
               then a warning will be printed if an attempt is made to run the
               nonexistent program.  Also,  the  xscreensaver-demo(1)  program
               will  suppress  the non-existent programs from the list if this
               is true.  Default: false.

       GetViewPortIsFullOfLies (class Boolean)
               Set this to true if the xscreensaver window doesn't  cover  the
               whole  screen.   This  works  around a longstanding XFree86 bug
               #421.  See the xscreensaver FAQ for details.

       font (class Font)
               The font used for the stdout/stderr text, if  captureStderr  is
               true.   Default  *-medium-r-*-140-*-m-* (a 14 point fixed-width

       mode (class Mode)
               Controls the behavior of xscreensaver.  Legal values are:

               random  When blanking the screen, select a random display  mode
                       from among those that are enabled and applicable.  This
                       is the default.

                       Like random, but if there are  multiple  screens,  each
                       screen  will  run the same random display mode, instead
                       of each screen running a different one.

               one     When blanking the screen, only ever use one  particular
                       display   mode  (the  one  indicated  by  the  selected

               blank   When blanking the screen, just go black: don't run  any
                       graphics hacks.

               off     Don't  ever  blank the screen, and don't ever allow the
                       monitor to power down.

       selected (class Integer)
               When mode is set to one, this is  the  one,  indicated  by  its
               index in the programs list.  You're crazy if you count them and
               set this number by hand: let  xscreensaver-demo(1)  do  it  for

       programs (class Programs)
               The  graphics  hacks  which  xscreensaver runs when the user is
               idle.  The value of this resource is a multi-line  string,  one
               sh-syntax command per line.  Each line must contain exactly one
               command: no semicolons, no ampersands.

               When the screensaver  starts  up,  one  of  these  is  selected
               (according  to  the  mode  setting),  and run.  After the cycle
               period expires, it is killed, and another is selected and run.

               If a line begins with a dash (-) then that  particular  program
               is  disabled:  it  won't  be selected at random (though you can
               still  select  it  explicitly  using  the  xscreensaver-demo(1)

               If all programs are disabled, then the screen will just be made
               blank, as when mode is set to blank.

               To disable a program, you must mark it as disabled with a  dash
               instead  of  removing  it  from  the list.  This is because the
               system-wide   (app-defaults)   and   per-user   (.xscreensaver)
               settings  are  merged  together,  and if a user just deletes an
               entry from their programs list, but that entry still exists  in
               the  system-wide list, then it will come back.  However, if the
               user disables it, then their setting takes precedence.

               If the display has multiple screens, then a  different  program
               will  be  run  for  each  screen.  (All screens are blanked and
               unblanked simultaneously.)

               Note that you must escape the newlines; here is an  example  of
               how you might set this in your ~/.xscreensaver file:

               programs:  \
                      qix -root                          \n\
                      ico -r -faces -sleep 1 -obj ico    \n\
                      xdaliclock -builtin2 -root         \n\
                      xv -root -rmode 5 image.gif -quit  \n
               Make  sure  your $PATH environment variable is set up correctly
               before xscreensaver is launched, or it won't be  able  to  find
               the programs listed in the programs resource.

               To  use  a  program  as a screensaver, two things are required:
               that that program draw on the root window (or  be  able  to  be
               configured  to  draw on the root window); and that that program
               understand "virtual root" windows, as used  by  virtual  window
               managers such as tvtwm(1).  (Generally, this is accomplished by
               just including the  "vroot.h"  header  file  in  the  program's


               Because xscreensaver was created back when dinosaurs roamed the
               earth,  it  still  contains  support  for  some  things  you've
               probably   never  seen,  such  as  1-bit  monochrome  monitors,
               grayscale monitors, and monitors  capable  of  displaying  only
               8-bit colormapped images.

               If there are some programs that you want to run only when using
               a color display, and others that you  want  to  run  only  when
               using a monochrome display, you can specify that like this:
                      mono:   mono-program  -root        \n\
                      color:  color-program -root        \n\
               More  generally, you can specify the kind of visual that should
               be used for the window on which the program  will  be  drawing.
               For  example,  if  one program works best if it has a colormap,
               but another works best if it has a 24-bit visual, both  can  be
                      PseudoColor: cmap-program  -root   \n\
                      TrueColor:   24bit-program -root   \n\
               In  addition  to  the symbolic visual names described above (in
               the discussion of the visualID resource) one other visual  name
               is supported in the programs list:

                    This  is  like  default,  but also requests the use of the
                    default colormap, instead of a  private  colormap.   (That
                    is,  it  behaves as if the -no-install command-line option
                    was specified, but only for this particular  hack.)   This
                    is provided because some third-party programs that draw on
                    the root  window  (notably:  xv(1),  and  xearth(1))  make
                    assumptions  about  the  visual  and  colormap of the root
                    window: assumptions which xscreensaver can violate.

               If you specify a particular visual  for  a  program,  and  that
               visual does not exist on the screen, then that program will not
               be chosen to run.  This means that on  displays  with  multiple
               screens  of  different  depths, you can arrange for appropriate
               hacks to be run on each.  For example, if one screen  is  color
               and  the  other is monochrome, hacks that look good in mono can
               be run on one, and hacks that only look good in color will show
               up on the other.

       You shouldn't ever need to change the following resources:

       pointerPollTime (class Time)
               When  server  extensions  are  not  in  use,  this controls how
               frequently xscreensaver checks to see if the mouse position  or
               buttons have changed.  Default 5 seconds.

       pointerHysteresis (class Integer)
               If  the  mouse  moves  less  than this-many pixels in a second,
               ignore it (do not consider that to be "activity.")  This is  so
               that  the  screen  doesn't  un-blank  (or  fail  to blank) just
               because you bumped the desk.  Default: 10 pixels.

       windowCreationTimeout (class Time)
               When server extensions are not in use, this controls the  delay
               between  when windows are created and when xscreensaver selects
               events on them.  Default 30 seconds.

       initialDelay (class Time)
               When server extensions are not in use, xscreensaver  will  wait
               this  many seconds before selecting events on existing windows,
               under the assumption that xscreensaver is started  during  your
               login  procedure, and the window state may be in flux.  Default
               0.  (This used to default to 30, but that was back in the  days
               when slow machines and X terminals were more common...)

       procInterrupts (class Boolean)
               This resource controls whether the /proc/interrupts file should
               be consulted to decide whether the user is idle.  This  is  the
               default  if  xscreensaver  has  been compiled on a system which
               supports this mechanism (i.e., Linux systems.)

               The benefit to doing this is that xscreensaver  can  note  that
               the  user  is  active even when the X console is not the active
               one:  if  the  user  is  typing  in  another  virtual  console,
               xscreensaver  will  notice that and will fail to activate.  For
               example, if you're  playing  Quake  in  VGA-mode,  xscreensaver
               won't  wake  up  in the middle of your game and start competing
               for CPU.

               The drawback to doing this is that perhaps you really  do  want
               idleness  on the X console to cause the X display to lock, even
               if there is activity on other virtual consoles.   If  you  want
               that,  then  set  this  option  to  False.  (Or just lock the X
               console manually.)

               The default value for this resource is True, on  systems  where
               it works.

       overlayStderr (class Boolean)
               If  captureStderr  is  True, and your server supports "overlay"
               visuals, then the text will be written into one of  the  higher
               layers   instead   of  into  the  same  layer  as  the  running
               screenhack.  Set this to False  to  disable  that  (though  you
               shouldn't need to.)

       overlayTextForeground (class Foreground)
               The  foreground  color  used  for  the  stdout/stderr  text, if
               captureStderr is true.  Default: Yellow.

       overlayTextBackground (class Background)
               The background  color  used  for  the  stdout/stderr  text,  if
               captureStderr is true.  Default: Black.

       bourneShell (class BourneShell)
               The  pathname  of  the  shell  that  xscreensaver uses to start
               subprocesses.  This must be  whatever  your  local  variant  of
               /bin/sh is: in particular, it must not be csh.


       DISPLAY to  get  the default host and display number, and to inform the
               sub-programs of the screen on which to draw.

               Passed to sub-programs to indicate the  ID  of  the  window  on
               which  they  should  draw.  This is necessary on Xinerama/RANDR
               systems where multiple physical monitors  share  a  single  X11

       PATH    to find the sub-programs to run.

       HOME    for the directory in which to read the .xscreensaver file.

               to  get  the  name of a resource file that overrides the global
               resources stored in the RESOURCE_MANAGER property.


       The latest version of xscreensaver, an online version of  this  manual,
       and a FAQ can always be found at


       X(1),     Xsecurity(1),    xauth(1),    xdm(1),    gdm(1),    xhost(1),
       xscreensaver-demo(1),                          xscreensaver-command(1),
       xscreensaver-gl-helper(1),                    xscreensaver-getimage(1),


       Copyright © 1991-2011 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


       Jamie Zawinski <>.  Written in late 1991; version 1.0 posted
       to comp.sources.x on 17-Aug-1992.

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

       And a huge thank you to the hundreds of people who have contributed, in
       large  ways and small, to the xscreensaver collection over the past two