Provided by: xscreensaver_5.15-2ubuntu1_amd64 bug

NAME

       xscreensaver-demo - interactively control the background xscreensaver daemon

SYNOPSIS

       xscreensaver-demo [-display host:display.screen] [-prefs] [--debug]

DESCRIPTION

       The  xscreensaver-demo program is a graphical front-end for setting the parameters used by
       the background xscreensaver(1) daemon.  It is essentially two things: a tool  for  editing
       the  ~/.xscreensaver  file;  and  a  tool  for demoing the various graphics hacks that the
       xscreensaver daemon will launch.

       The main window consists of a menu bar and two  tabbed  pages.   The  first  page  is  for
       editing  the  list of demos, and the second is for editing various other parameters of the
       screensaver.

MENU COMMANDS

       All of these commands are on either the File or Help menus:

       Blank Screen Now
           Activates the background xscreensaver daemon, which will then run a  demo  at  random.
           This is the same as running xscreensaver-command(1) with the -activate option.

       Lock Screen Now
           Just  like  Blank  Screen Now, except the screen will be locked as well (even if it is
           not configured to lock all the time.)  This  is  the  same  as  running  xscreensaver-
           command(1) with the -lock option.

       Kill Daemon
           If  the  xscreensaver  daemon is running on this screen, kill it.  This is the same as
           running xscreensaver-command(1) with the -exit option.

       Restart Daemon
           If the xscreensaver daemon is running on this screen, kill it.  Then launch it  again.
           This is the same as doing ``xscreensaver-command -exit'' followed by ``xscreensaver''.

           Note that it is not the same as doing ``xscreensaver-command -restart''.

       Exit
           Exits  the  xscreensaver-demo  program (this program) without affecting the background
           xscreensaver daemon, if any.

       About...
           Displays the version number of this program, xscreensaver-demo.

       Documentation...
           Opens up a web browser looking at the XScreenSaver web page, where you can find online
           copies  of  the  xscreensaver(1),  xscreensaver-demo(1),  and  xscreensaver-command(1)
           manuals.

DISPLAY MODES TAB

       This page contains a list of the names of the various display modes, a preview  area,  and
       some fields that let you configure screen saver behavior.

       Mode
           This  option  menu  controls the activation behavior of the screen saver.  The options
           are:

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

           Blank Screen Only
               When blanking the screen, just go black: don't run any graphics.

           Only One Screen Saver
               When blanking the screen, only ever use  one  particular  display  mode  (the  one
               selected in the list.)

           Random Screen Saver
               When  blanking  the screen, select a random display mode from among those that are
               enabled and applicable.  If there are multiple monitors connected, run a different
               display mode on each one.  This is the default.

           Random Same Saver
               This  is  just  like  Random  Screen  Saver,  except that the same randomly-chosen
               display mode will be run on all monitors, instead of different ones on each.

       Demo List
           Double-clicking in the list on the left will let you try out the indicated demo.   The
           screen  will  go black, and the program will run in full-screen mode, just as it would
           if the xscreensaver daemon had launched it.  Clicking the mouse again  will  stop  the
           demo and un-blank the screen.

           Single-clicking  in the list will run it in the small preview pane on the right.  (But
           beware: many of the display modes behave somewhat differently when  running  in  full-
           screen mode, so the scaled-down view might not give an accurate impression.)

           When  Mode is set to Random Screen Saver, each name in the list has a checkbox next to
           it: this controls whether this display mode is enabled.  If it is unchecked, then that
           mode  will  not be chosen.  (Though you can still run it explicitly by double-clicking
           on its name.)

       Arrow Buttons
           Beneath the list are a pair of up and down arrows. Clicking on  the  down  arrow  will
           select  the next item in the list, and then run it in full-screen mode, just as if you
           had double-clicked on it.  The up arrow goes the other way.  This is just  a  shortcut
           for trying out all of the display modes in turn.

       Blank After
           After the user has been idle this long, the xscreensaver daemon will blank the screen.

       Cycle After
           After  the  screensaver has been running for this long, the currently running graphics
           demo will be killed, and a new one started.  If this is 0, then the graphics demo will
           never  be changed: only one demo will run until the screensaver is deactivated by user
           activity.

       Lock Screen
           When this is checked, the screen will be locked when it activates.

       Lock Screen After
           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 minutes, and
           Blank After is 10 minutes, 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  Screen  After
           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.

       Preview
           This button, below the small preview window, runs the demo in full-screen mode so that
           you can try it out.  This is the same thing that  happens  when  you  double-click  an
           element in the list.  Click the mouse to dismiss the full-screen preview.

       Settings
           This  button  will  pop  up  a dialog where you can configure settings specific to the
           display mode selected in the list.

SETTINGS DIALOG

       When you click on the Settings button on the Display Modes  tab,  a  configuration  dialog
       will  pop  up that lets you customize settings of the selected display mode.  Each display
       mode has its own custom configuration controls on the left side.

       On the right side is a paragraph or two describing the display  mode.   Below  that  is  a
       Documentation button that will display the display mode's manual page, if it has one, in a
       new window (since each of the display modes is actually a separate program, they each have
       their own manual.)

       The  Advanced  button  reconfigures the dialog box so that you can edit the display mode's
       command line directly, instead of using the graphical controls.

ADVANCED TAB

       This tab lets you change various settings used by the xscreensaver daemon itself, as  well
       as some global options shared by all of the display modes.

       Image Manipulation

       Some  of  the graphics hacks manipulate images.  These settings control where those source
       images come from.  (All of these options work  by  invoking  the  xscreensaver-getimage(1)
       program, which is what actually does the work.)

           Grab Desktop Images
               If this option is selected, then they are allowed to manipulate the desktop image,
               that is, a display mode might draw a picture of your  desktop  melting,  or  being
               distorted  in  some way.  The security-paranoid might want to disable this option,
               because if it is set, it means that the windows on your desktop will  occasionally
               be  visible  while your screen is locked.  Others will not be able to do anything,
               but they may be able to see whatever you left on your screen.

           Grab Video Frames
               If your system has a video capture card, selecting  this  option  will  allow  the
               image-manipulating modes to capture a frame of video to operate on.

           Choose Random Image
               If  this  option  is  set,  then the image-manipulating modes will select a random
               image file to operate on, from the specified source.  That source may be  a  local
               directory,  which  will be recursively searched for images.  Or, it may be the URL
               of an RSS or Atom feed (e.g., a Flickr gallery), in which case a random image from
               that  feed  will  be  selected  instead.   The contents of the feed will be cached
               locally and refreshed periodically as needed.

           If more than one of the above image-related options are selected,  then  one  will  be
           chosen at random.  If none of them are selected, then an image of video colorbars will
           be used instead.

       Text Manipulation

       Some of the display modes display and manipulate text.  The following options control  how
       that   text   is   generated.    (These   parameters   control   the   behavior   of   the
       xscreensaver-text(1) program, which is what actually does the work.)

           Host Name and Time
               If this checkbox is selected, then the text used by the screen savers will be  the
               local host name, OS version, date, time, and system load.

           Text
               If  this  checkbox  is  selected,  then the literal text typed in the field to its
               right will be used.  If it contains % escape sequences, they will be  expanded  as
               per strftime(2).

           Text File
               If  this checkbox is selected, then the contents of the corresponding file will be
               displayed.

           Program
               If this checkbox is selected, then the given program will be run, repeatedly,  and
               its output will be displayed.

           URL If  this  checkbox  is  selected,  then  the given HTTP URL will be downloaded and
               displayed repeatedly.  If the document contains HTML, RSS, or  Atom,  it  will  be
               converted to plain-text first.

               Note: this re-downloads the document every time the screen saver runs out of text,
               so it will probably be hitting that  web  server  multiple  times  a  minute.   Be
               careful that the owner of that server doesn't consider that to be abusive.

       Power Management Settings

       These settings control whether, and when, your monitor powers down.

           Power Management Enabled
               Whether the monitor should be powered down after a period of inactivity.

               If  this  option  is grayed out, it means 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 this 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 only  adjust  the  power-saving
               delays by changing settings in the BIOS in some hardware-specific way.

           Standby After
               If Power Management Enabled is selected, the monitor will go black after this much
               idle time.  (Graphics demos will stop running, also.)

           Suspend After
               If Power Management Enabled is selected, the monitor  will  go  into  power-saving
               mode  after this much idle time.  This duration should be greater than or equal to
               Standby.

           Off After
               If Power Management Enabled is selected, the monitor will fully power  down  after
               this much idle time.  This duration should be greater than or equal to Suspend.

           Quick Power-off in Blank Only Mode
               If  the  display  mode  is  set to Blank Screen Only and this is checked, then the
               monitor will be powered off immediately upon blanking,  regardless  of  the  other
               power-management  settings.   In this way, the power management idle-timers can be
               completely disabled, but the screen will be powered off when black.   (This  might
               be preferable on laptops.)

       Fading and Colormaps

       These  options control how the screen fades to or from black when a screen saver begins or
       ends.

           Fade To Black When Blanking
               If selected, then when the screensaver activates,  the  current  contents  of  the
               screen will fade to black instead of simply winking out.  (Note: this doesn't work
               with all X servers.)  A fade will also be done when switching graphics hacks (when
               the Cycle After expires.)

           Unfade From Black When Unblanking
               The   complement  to  Fade  Colormap:  if  selected,  then  when  the  screensaver
               deactivates, the original contents of the screen will fade in from  black  instead
               of appearing immediately.  This is only done if Fade Colormap is also selected.

           Fade Duration
               When fading or unfading are selected, this controls how long the fade will take.

           Install Colormap
               On  8-bit  screens, whether to install a private colormap while the screensaver is
               active, so that the graphics hacks can get as many colors as possible.  This  does
               nothing if you are running in 16-bit or better.

       There  are  more settings than these available, but these are the most commonly used ones;
       see the manual for xscreensaver(1) for other parameters that can be  set  by  editing  the
       ~/.xscreensaver file, or the X resource database.

COMMAND-LINE OPTIONS

       xscreensaver-demo accepts the following command line options.

       -display host:display.screen
               The  X display to use.  The xscreensaver-demo program will open its window on that
               display, and also control the xscreensaver  daemon  that  is  managing  that  same
               display.

       -prefs  Start  up  with  the Advanced tab selected by default instead of the Display Modes
               tab.

       -debug  Causes lots of diagnostics to be printed on stderr.

       It is important that the xscreensaver and xscreensaver-demo processes be  running  on  the
       same   machine,   or   at  least,  on  two  machines  that  share  a  file  system.   When
       xscreensaver-demo writes a new version of the ~/.xscreensaver file,  it's  important  that
       the  xscreensaver  see  that  same  file.   If  the  two  processes  are  seeing different
       ~/.xscreensaver files, things will malfunction.

ENVIRONMENT

       DISPLAY to get the default host and display number.

       PATH    to find the sub-programs to run.  However, note that the sub-programs are actually
               launched  by  the  xscreensaver daemon, not by xscreensaver-demo itself.  So, what
               matters is what $PATH that the xscreensaver program sees.

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

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

       HTTP_PROXY or http_proxy
               to get the default HTTP proxy host and port.

UPGRADES

       The latest version of xscreensaver, an online version of this manual, and a FAQ can always
       be found at http://www.jwz.org/xscreensaver/

SEE ALSO

       X(1),      xscreensaver(1),       xscreensaver-command(1),       xscreensaver-getimage(1),
       xscreensaver-text(1)

COPYRIGHT

       Copyright © 1992-2011 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 warranty.

AUTHOR

       Jamie Zawinski <jwz@jwz.org>, 13-aug-92.

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