1xscreensaver(1) XScreenSaver manual xscreensaver(1)
2
6 xscreensaver - extensible screen saver framework, plus locking
7
9 xscreensaver [-display host:display.screen] [-verbose] [-no-cap‐
10 ture-stderr] [-no-splash]
11
13 The xscreensaver program waits until the keyboard and mouse have been
14 idle for a period, and then runs a graphics demo chosen at random. It
15 turns off as soon as there is any mouse or keyboard activity.
16 This program can lock your terminal in order to prevent others from
18 using it, though its default mode of operation is merely to display
19 pretty pictures on your screen when it is not in use.
20 It also provides configuration and control of your monitor's power-sav‐
22 ing features.
23
25 For the impatient, try this:
26 xscreensaver &
27 xscreensaver-demo
28 The xscreensaver-demo(1) program pops up a dialog box that lets you
29 configure the screen saver, and experiment with the various display
30 modes.
31 Note: unlike xlock(1), xscreensaver has a client-server model: the
33 xscreensaver program is a daemon that runs in the background; it is
34 controlled by the foreground xscreensaver-demo(1) and xscreensaver-com‐
35 mand(1) programs.
36
38 The easiest way to configure xscreensaver is to simply run the xscreen‐
39 saver-demo(1) program, and change the settings through the GUI. The
40 rest of this manual page describes lower level ways of changing set‐
41 tings.
42 I'll repeat that because it's important:
44 The easy way to configure xscreensaver is to run the xscreensaver-
46 demo(1) program. You shouldn't need to know any of the stuff
47 described in this manual unless you are trying to do something
48 tricky, like customize xscreensaver for site-wide use or something.
49 Options to xscreensaver are stored in one of two places: in a .xscreen‐
51 saver file in your home directory; or in the X resource database. If
52 the .xscreensaver file exists, it overrides any settings in the
53 resource database.
54 The syntax of the .xscreensaver file is similar to that of the .Xde‐
56 faults file; for example, to set the timeout paramter in the .xscreen‐
57 saver file, you would write the following:
58 timeout: 5
59 whereas, in the .Xdefaults file, you would write
60 xscreensaver.timeout: 5
61 If you change a setting in the .xscreensaver file while xscreensaver is
62 already running, it will notice this, and reload the file. (The file
63 will be reloaded the next time the screen saver needs to take some
64 action, such as blanking or unblanking the screen, or picking a new
65 graphics mode.)
66 If you change a setting in your X resource database, or if you want
68 xscreensaver to notice your changes immediately instead of the next
69 time it wakes up, then you will need to reload your .Xdefaults file,
70 and then tell the running xscreensaver process to restart itself, like
71 so:
72 xrdb < ~/.Xdefaults
73 xscreensaver-command -restart
74 If you want to set the system-wide defaults, then make your edits to
75 the xscreensaver app-defaults file, which should have been installed
76 when xscreensaver itself was installed. The app-defaults file will
77 usually be named /usr/lib/X11/app-defaults/XScreenSaver, but different
78 systems might keep it in a different place (for example, /usr/open‐
79 win/lib/app-defaults/XScreenSaver on Solaris.)
80 When settings are changed in the Preferences dialog box (see above) the
82 current settings will be written to the .xscreensaver file. (The .Xde‐
83 faults file and the app-defaults file will never be written by xscreen‐
84 saver itself.)
85 timeout (class Time)
87 The screensaver will activate (blank the screen) after the key‐
88 board and mouse have been idle for this many minutes. Default
89 10 minutes.
90 cycle (class Time)
92 After the screensaver has been running for this many minutes,
93 the currently running graphics-hack sub-process will be killed
94 (with SIGTERM), and a new one started. If this is 0, then the
95 graphics hack will never be changed: only one demo will run
96 until the screensaver is deactivated by user activity. Default
97 10 minutes.
98 lock (class Boolean)
100 Enable locking: before the screensaver will turn off, it will
101 require you to type the password of the logged-in user (really,
102 the person who ran xscreensaver), or the root password. (Note:
103 this doesn't work if the screensaver is launched by xdm(1)
104 because it can't know the user-id of the logged-in user. See
105 the ``Using XDM(1)'' section, below.
106 lockTimeout (class Time)
108 If locking is enabled, this controls the length of the ``grace
109 period'' between when the screensaver activates, and when the
110 screen becomes locked. For example, if this is 5, and -timeout
111 is 10, then after 10 minutes, the screen would blank. If there
112 was user activity at 12 minutes, no password would be required
113 to un-blank the screen. But, if there was user activity at 15
114 minutes or later (that is, -lock-timeout minutes after activa‐
115 tion) then a password would be required. The default is 0,
116 meaning that if locking is enabled, then a password will be
117 required as soon as the screen blanks.
118 passwdTimeout (class Time)
120 If the screen is locked, then this is how many seconds the
121 password dialog box should be left on the screen before giving
122 up (default 30 seconds.) This should not be too large: the X
123 server is grabbed for the duration that the password dialog box
124 is up (for security purposes) and leaving the server grabbed
125 for too long can cause problems.
126 dpmsEnabled (class Boolean)
128 Whether power management is enabled.
129 dpmsStandby (class Time)
131 If power management is enabled, how long until the monitor goes
132 solid black.
133 dpmsSuspend (class Time)
135 If power management is enabled, how long until the monitor goes
136 into power-saving mode.
137 dpmsOff (class Time)
139 If power management is enabled, how long until the monitor pow‐
140 ers down completely. Note that these settings will have no
141 effect unless both the X server and the display hardware sup‐
142 port power management; not all do. See the Power Management
143 section, below, for more information.
144 visualID (class VisualID)
146 Specify which X visual to use by default. (Note carefully that
147 this resource is called visualID, not merely visual; if you set
148 the visual resource instead, things will malfunction in obscure
149 ways for obscure reasons.)
150 Legal values for the VisualID resource are:
152 default Use the screen's default visual (the visual of the root
154 window.) This is the default.
155 best Use the visual which supports the most colors. Note,
157 however, that the visual with the most colors might be
158 a TrueColor visual, which does not support colormap
159 animation. Some programs have more interesting behav‐
160 ior when run on PseudoColor visuals than on TrueColor.
161 mono Use a monochrome visual, if there is one.
163 gray Use a grayscale or staticgray visual, if there is one
165 and it has more than one plane (that is, it's not mono‐
166 chrome.)
167 color Use the best of the color visuals, if there are any.
169 GL Use the visual that is best for OpenGL programs.
171 (OpenGL programs have somewhat different requirements
172 than other X programs.)
173 class where class is one of StaticGray, StaticColor, True‐
175 Color, GrayScale, PseudoColor, or DirectColor. Selects
176 the deepest visual of the given class.
177 number where number (decimal or hex) is interpreted as a vis‐
179 ual id number, as reported by the xdpyinfo(1) program;
180 in this way you can have finer control over exactly
181 which visual gets used, for example, to select a shal‐
182 lower one than would otherwise have been chosen.
183 Note that this option specifies only the default visual that
185 will be used: the visual used may be overridden on a program-
186 by-program basis. See the description of the programs
187 resource, below.
188 installColormap (class Boolean)
190 On PseudoColor (8-bit) displays, install a private colormap
191 while the screensaver is active, so that the graphics hacks can
192 get as many colors as possible. This is the default. (This
193 only applies when the screen's default visual is being used,
194 since non-default visuals get their own colormaps automati‐
195 cally.) This can also be overridden on a per-hack basis: see
196 the discussion of the default-n name in the section about the
197 programs resource.
198 This does nothing if you have a TrueColor (16-bit or deeper)
200 display.
201 verbose (class Boolean)
203 Whether to print diagnostics. Default false.
204 timestamp (class Boolean)
206 Whether to print the time of day along with any other diagnos‐
207 tic messages. Default true.
208 splash (class Boolean)
210 Whether to display a splash screen at startup. Default true.
211 splashDuration (class Time)
213 How long the splash screen should remain visible; default 5
214 seconds.
215 quad (class Boolean)
217 If true, then four screensavers will be run on each monitor.
218 Use at your own risk!
219 helpURL (class URL)
221 The splash screen has a Help button on it. When you press it,
222 it will display the web page indicated here in your web
223 browser.
224 loadURL (class LoadURL)
226 This is the shell command used to load a URL into your web
227 browser. The default setting will load it into Mozilla/Net‐
228 scape if it is already running, otherwise, will launch a new
229 browser looking at the helpURL.
230 demoCommand (class DemoCommand)
232 This is the shell command run when the Demo button on the
233 splash window is pressed. It defaults to xscreensaver-demo(1).
234 prefsCommand (class PrefsCommand)
236 This is the shell command run when the Prefs button on the
237 splash window is pressed. It defaults to xscreen‐
238 saver-demo -prefs.
239 nice (class Nice)
241 The sub-processes created by xscreensaver will be ``niced'' to
242 this level, so that they are given lower priority than other
243 processes on the system, and don't increase the load unneces‐
244 sarily. The default is 10.
245 (Higher numbers mean lower priority; see nice(1) for details.)
247 fade (class Boolean)
249 If this is true, then when the screensaver activates, the cur‐
250 rent contents of the screen will fade to black instead of sim‐
251 ply winking out. This only works on certain systems. A fade
252 will also be done when switching graphics hacks (when the cycle
253 timer expires.) Default: true.
254 unfade (class Boolean)
256 If this is true, then when the screensaver deactivates, the
257 original contents of the screen will fade in from black instead
258 of appearing immediately. This only works on certain systems,
259 and if fade is true as well. Default false.
260 fadeSeconds (class Time)
262 If fade is true, this is how long the fade will be in seconds
263 (default 3 seconds.)
264 fadeTicks (class Integer)
266 If fade is true, this is how many times a second the colormap
267 will be changed to effect a fade. Higher numbers yield
268 smoother fades, but may make the fades take longer than the
269 specified fadeSeconds if your server isn't fast enough to keep
270 up. Default 20.
271 captureStderr (class Boolean)
273 Whether xscreensaver should redirect its stdout and stderr
274 streams to the window itself. Since its nature is to take over
275 the screen, you would not normally see error messages generated
276 by xscreensaver or the sub-programs it runs; this resource will
277 cause the output of all relevant programs to be drawn on the
278 screensaver window itself, as well as being written to the con‐
279 trolling terminal of the screensaver driver process. Default
280 true.
281 ignoreUninstalledPrograms (class Boolean)
283 There may be programs in the list that are not installed on the
284 system, yet are marked as "enabled." If this preference is
285 true, then such programs will simply be ignored. If false,
286 then a warning will be printed if an attempt is made to run the
287 nonexistent program. Also, the xscreensaver-demo(1) program
288 will suppress the non-existent programs from the list if this
289 is true. Default: false.
290 GetViewPortIsFullOfLies (class Boolean)
292 Set this to true if the xscreensaver window doesn't cover the
293 whole screen. This works around a longstanding XFree86 bug
294 #421. See the xscreensaver FAQ for details.
295 font (class Font)
297 The font used for the stdout/stderr text, if captureStderr is
298 true. Default *-medium-r-*-140-*-m-* (a 14 point fixed-width
299 font.)
300 mode (class Mode)
302 Controls the behavior of xscreensaver. Legal values are:
303 random When blanking the screen, select a random display mode
305 from among those that are enabled and applicable. This
306 is the default.
307 random-same
309 Like random, but if there are multiple screens, each
310 screen will run the same random display mode, instead
311 of each screen running a different one.
312 one When blanking the screen, only ever use one particular
314 display mode (the one indicated by the selected set‐
315 ting.)
316 blank When blanking the screen, just go black: don't run any
318 graphics hacks.
319 off Don't ever blank the screen, and don't ever allow the
321 monitor to power down.
322 selected (class Integer)
325 When mode is set to one, this is the one, indicated by its
326 index in the programs list. You're crazy if you count them and
327 set this number by hand: let xscreensaver-demo(1) do it for
328 you!
329 programs (class Programs)
331 The graphics hacks which xscreensaver runs when the user is
332 idle. The value of this resource is a multi-line string, one
333 sh-syntax command per line. Each line must contain exactly one
334 command: no semicolons, no ampersands.
335 When the screensaver starts up, one of these is selected
337 (according to the mode setting), and run. After the cycle
338 period expires, it is killed, and another is selected and run.
339 If a line begins with a dash (-) then that particular program
341 is disabled: it won't be selected at random (though you can
342 still select it explicitly using the xscreensaver-demo(1) pro‐
343 gram.)
344 If all programs are disabled, then the screen will just be made
346 blank, as when mode is set to blank.
347 To disable a program, you must mark it as disabled with a dash
349 instead of removing it from the list. This is because the sys‐
350 tem-wide (app-defaults) and per-user (.xscreensaver) settings
351 are merged together, and if a user just deletes an entry from
352 their programs list, but that entry still exists in the system-
353 wide list, then it will come back. However, if the user dis‐
354 ables it, then their setting takes precedence.
355 If the display has multiple screens, then a different program
357 will be run for each screen. (All screens are blanked and
358 unblanked simultaneously.)
359 Note that you must escape the newlines; here is an example of
361 how you might set this in your ~/.xscreensaver file:
362 programs: \
364 qix -root \n\
365 ico -r -faces -sleep 1 -obj ico \n\
366 xdaliclock -builtin2 -root \n\
367 xv -root -rmode 5 image.gif -quit \n
368 Make sure your $PATH environment variable is set up correctly
369 before xscreensaver is launched, or it won't be able to find
370 the programs listed in the programs resource.
371 To use a program as a screensaver, two things are required:
373 that that program draw on the root window (or be able to be
374 configured to draw on the root window); and that that program
375 understand ``virtual root'' windows, as used by virtual window
376 managers such as tvtwm(1). (Generally, this is accomplished by
377 just including the "vroot.h" header file in the program's
378 source.)
379 If there are some programs that you want to run only when using
381 a color display, and others that you want to run only when
382 using a monochrome display, you can specify that like this:
383 mono: mono-program -root \n\
384 color: color-program -root \n\
385 More generally, you can specify the kind of visual that should
386 be used for the window on which the program will be drawing.
387 For example, if one program works best if it has a colormap,
388 but another works best if it has a 24-bit visual, both can be
389 accommodated:
390 PseudoColor: cmap-program -root \n\
391 TrueColor: 24bit-program -root \n\
392 In addition to the symbolic visual names described above (in
393 the discussion of the visualID resource) one other visual name
394 is supported in the programs list:
395 default-n
397 This is like default, but also requests the use of the
398 default colormap, instead of a private colormap. (That
399 is, it behaves as if the -no-install command-line option
400 was specified, but only for this particular hack.) This
401 is provided because some third-party programs that draw on
402 the root window (notably: xv(1), and xearth(1)) make
403 assumptions about the visual and colormap of the root win‐
404 dow: assumptions which xscreensaver can violate.
405 If you specify a particular visual for a program, and that vis‐
407 ual does not exist on the screen, then that program will not be
408 chosen to run. This means that on displays with multiple
409 screens of different depths, you can arrange for appropriate
410 hacks to be run on each. For example, if one screen is color
411 and the other is monochrome, hacks that look good in mono can
412 be run on one, and hacks that only look good in color will show
413 up on the other.
414 You shouldn't ever need to change the following resources:
416 pointerPollTime (class Time)
418 When server extensions are not in use, this controls how fre‐
419 quently xscreensaver checks to see if the mouse position or
420 buttons have changed. Default 5 seconds.
421 pointerHysteresis (class Integer)
423 If the mouse moves less than this-many pixels in a second,
424 ignore it (do not consider that to be "activity.") This is so
425 that the screen doesn't un-blank (or fail to blank) just
426 because you bumped the desk. Default: 10 pixels.
427 windowCreationTimeout (class Time)
429 When server extensions are not in use, this controls the delay
430 between when windows are created and when xscreensaver selects
431 events on them. Default 30 seconds.
432 initialDelay (class Time)
434 When server extensions are not in use, xscreensaver will wait
435 this many seconds before selecting events on existing windows,
436 under the assumption that xscreensaver is started during your
437 login procedure, and the window state may be in flux. Default
438 0. (This used to default to 30, but that was back in the days
439 when slow machines and X terminals were more common...)
440 There are a number of different X server extensions which can make
442 xscreensaver's job easier. The next few resources specify whether
443 these extensions should be utilized if they are available.
444 sgiSaverExtension (class Boolean)
446 This resource controls whether the SGI SCREEN_SAVER server
447 extension will be used to decide whether the user is idle.
448 This is the default if xscreensaver has been compiled with sup‐
449 port for this extension (which is the default on SGI systems.).
450 If it is available, the SCREEN_SAVER method is faster and more
451 reliable than what will be done otherwise, so use it if you
452 can. (This extension is only available on Silicon Graphics
453 systems, unfortunately.)
454 mitSaverExtension (class Boolean)
456 This resource controls whether the MIT-SCREEN-SAVER server
457 extension will be used to decide whether the user is idle.
458 However, the default for this resource is false, because even
459 if this extension is available, it is flaky (and it also makes
460 the fade option not work properly.) Use of this extension is
461 strongly discouraged. Support for it will probably be removed
462 eventually.
463 xidleExtension (class Boolean)
465 This resource controls whether the XIDLE server extension will
466 be used to decide whether the user is idle. This is the
467 default if xscreensaver has been compiled with support for this
468 extension. (This extension is only available for X11R4 and
469 X11R5 systems, unfortunately.)
470 procInterrupts (class Boolean)
472 This resource controls whether the /proc/interrupts file should
473 be consulted to decide whether the user is idle. This is the
474 default if xscreensaver has been compiled on a system which
475 supports this mechanism (i.e., Linux systems.)
476 The benefit to doing this is that xscreensaver can note that
478 the user is active even when the X console is not the active
479 one: if the user is typing in another virtual console, xscreen‐
480 saver will notice that and will fail to activate. For example,
481 if you're playing Quake in VGA-mode, xscreensaver won't wake up
482 in the middle of your game and start competing for CPU.
483 The drawback to doing this is that perhaps you really do want
485 idleness on the X console to cause the X display to lock, even
486 if there is activity on other virtual consoles. If you want
487 that, then set this option to False. (Or just lock the X con‐
488 sole manually.)
489 The default value for this resource is True, on systems where
491 it works.
492 overlayStderr (class Boolean)
494 If captureStderr is True, and your server supports ``overlay''
495 visuals, then the text will be written into one of the higher
496 layers instead of into the same layer as the running screen‐
497 hack. Set this to False to disable that (though you shouldn't
498 need to.)
499 overlayTextForeground (class Foreground)
501 The foreground color used for the stdout/stderr text, if cap‐
502 tureStderr is true. Default: Yellow.
503 overlayTextBackground (class Background)
505 The background color used for the stdout/stderr text, if cap‐
506 tureStderr is true. Default: Black.
507 bourneShell (class BourneShell)
509 The pathname of the shell that xscreensaver uses to start sub‐
510 processes. This must be whatever your local variant of /bin/sh
511 is: in particular, it must not be csh.
512
514 xscreensaver also accepts a few command-line options, mostly for use
515 when debugging: for normal operation, you should configure things via
516 the ~/.xscreensaver file.
517 -display host:display.screen
519 The X display to use. For displays with multiple screens,
520 XScreenSaver will manage all screens on the display simultan‐
521 iously.
522 -verbose
524 Same as setting the verbose resource to true: print diagnostics
525 on stderr and on the xscreensaver window.
526 -no-capture-stderr
528 Same as setting the captureStderr resource to false: do not re‐
529 direct the stdout and stderr streams to the xscreensaver window
530 itself. If xscreensaver is crashing, you might need to do this
531 in order to see the error message.
532
534 When it is time to activate the screensaver, a full-screen black window
535 is created on each screen of the display. Each window is created in
536 such a way that, to any subsequently-created programs, it will appear
537 to be a ``virtual root'' window. Because of this, any program which
538 draws on the root window (and which understands virtual roots) can be
539 used as a screensaver.
540 When the user becomes active again, the screensaver windows are
542 unmapped, and the running subprocesses are killed by sending them
543 SIGTERM. This is also how the subprocesses are killed when the screen‐
544 saver decides that it's time to run a different demo: the old one is
545 killed and a new one is launched.
546 Before launching a subprocess, xscreensaver stores an appropriate value
548 for $DISPLAY in the environment that the child will receive. (This is
549 so that if you start xscreensaver with a -display argument, the pro‐
550 grams which xscreensaver launches will draw on the same display; and so
551 that the child will end up drawing on the appropriate screen of a
552 multi-headed display.)
553 When the screensaver turns off, or is killed, care is taken to restore
555 the ``real'' virtual root window if there is one. Because of this, it
556 is important that you not kill the screensaver process with kill -9 if
557 you are running a virtual-root window manager. If you kill it with -9,
558 you may need to restart your window manager to repair the damage. This
559 isn't an issue if you aren't running a virtual-root window manager.
560 For all the gory details, see the commentary at the top of xscreen‐
562 saver.c.
563 You can control a running screensaver process by using the xscreen‐
565 saver-command(1) program (which see.)
566
568 Modern X servers contain support to power down the monitor after an
569 idle period. If the monitor has powered down, then xscreensaver will
570 notice this (after a few minutes), and will not waste CPU by drawing
571 graphics demos on a black screen. An attempt will also be made to
572 explicitly power the monitor back up as soon as user activity is
573 detected.
574 As of version 3.28 (Feb 2001), the ~/.xscreensaver file controls the
576 configuration of your display's power management settings: if you have
577 used xset(1) to change your power management settings, then xscreen‐
578 saver will override those changes with the values specified in
579 ~/.xscreensaver (or with its built-in defaults, if there is no
580 ~/.xscreensaver file yet.)
581 To change your power management settings, run xscreensaver-demo(1) and
583 change the various timeouts through the user interface. Alternately,
584 you can edit the ~/.xscreensaver file directly.
585 If the power management section is grayed out in the xscreen‐
587 saver-demo(1) window, then that means that your X server does not sup‐
588 port the XDPMS extension, and so control over the monitor's power state
589 is not available.
590 If you're using a laptop, don't be surprised if changing the DPMS set‐
592 tings has no effect: many laptops have monitor power-saving behavior
593 built in at a very low level that is invisible to Unix and X. On such
594 systems, you can typically adjust the power-saving delays only by
595 changing settings in the BIOS in some hardware-specific way.
596 If DPMS seems not to be working with XFree86, make sure the "DPMS"
598 option is set in your /etc/X11/XF86Config file. See the XF86Config(5)
599 manual for details.
600
602 You can run xscreensaver from your xdm(1) session, so that the screen‐
603 saver will run even when nobody is logged in on the console.
604 The trick to using xscreensaver with xdm is this: keep in mind the two
606 very different states in which xscreensaver will be running:
607 1: Nobody logged in.
609 If you're thinking of running xscreensaver from XDM at all, then
611 it's probably because you want graphics demos to be running on
612 the console when nobody is logged in there. In this case,
613 xscreensaver will function only as a screen saver, not a screen
614 locker: it doesn't make sense for xscreensaver to lock the
615 screen, since nobody is logged in yet! The only thing on the
616 screen is the XDM login prompt.
617 2: Somebody logged in.
619 Once someone has logged in through the XDM login window, the
621 situation is very different. For example: now it makes sense to
622 lock the screen (and prompt for the logged in user's password);
623 and now xscreensaver should consult that user's ~/.xscreensaver
624 file; and so on.
625 The difference between these two states comes down to a question of,
627 which user is the xscreensaver process running as? For the first
628 state, it doesn't matter. If you start xscreensaver in the usual XDM
629 way, then xscreensaver will probably end up running as root, which is
630 fine for the first case (the ``nobody logged in'' case.)
631 However, once someone is logged in, running as root is no longer fine:
633 because xscreensaver will be consulting root's .xscreensaver file
634 instead of that of the logged in user, and won't be prompting for the
635 logged in user's password, and so on. (This is not a security problem,
636 it's just not what you want.)
637 So, once someone has logged in, you want xscreensaver to be running as
639 that user. The way to accomplish this is to kill the old xscreensaver
640 process and start a new one (as the new user.)
641 The simplest way to accomplish all of this is as follows:
643 1: Launch xscreensaver before anyone logs in.
645 To the file /usr/lib/X11/xdm/Xsetup, add the lines
647 xhost +localhost
648 xscreensaver-command -exit
649 xscreensaver &
650 This will run xscreensaver as root, over the XDM login window.
651 Moving the mouse will cause the screen to un-blank, and allow
652 the user to type their password at XDM to log in.
653 2: Restart xscreensaver when someone logs in.
655 Near the top of the file /usr/lib/X11/xdm/Xsession, add those
657 same lines:
658 xscreensaver-command -exit
659 xscreensaver &
660 When someone logs in, this will kill off the existing (root)
661 xscreensaver process, and start a new one, running as the user
662 who has just logged in. If the user's .xscreensaver file
663 requests locking, they'll get it. They will also get their own
664 choice of timeouts, and graphics demos, and so on.
665 Alternately, each user could just put those lines in their per‐
667 sonal ~/.xsession files.
668 Make sure you have $PATH set up correctly in the Xsetup and Xsession
670 scripts, or xdm won't be able to find xscreensaver, and/or xscreensaver
671 won't be able to find its graphics demos.
672 (If your system does not seem to be executing the Xsetup file, you may
674 need to configure it to do so: the traditional way to do this is to
675 make that file the value of the DisplayManager*setup resource in the
676 /usr/lib/X11/xdm/xdm-config file. See the man page for xdm(1) for more
677 details.)
678 It is safe to run xscreensaver as root (as xdm is likely to do.) If
680 run as root, xscreensaver changes its effective user and group ids to
681 something safe (like "nobody") before connecting to the X server or
682 launching user-specified programs.
683 An unfortunate side effect of this (important) security precaution is
685 that it may conflict with cookie-based authentication.
686 If you get "connection refused" errors when running xscreensaver from
688 xdm, then this probably means that you have xauth(1) or some other
689 security mechanism turned on. One way around this is to add
690 "xhost +localhost" to Xsetup, just before xscreensaver is launched.
691 Note that this will give access to the X server to anyone capable of
693 logging in to the local machine, so in some environments, this might
694 not be appropriate. If turning off file-system-based access control is
695 not acceptable, then running xscreensaver from the Xsetup file might
696 not be possible, and xscreensaver will only work when running as a nor‐
697 mal, unprivileged user.
698 For more information on the X server's access control mechanisms, see
700 the man pages for X(1), Xsecurity(1), xauth(1), and xhost(1).
701
703 Using xscreensaver with gdm(1) is easy, because gdm has a configuration
704 tool. Just fire up gdmconfig(1) and on the Background page, type
705 "xscreensaver -nosplash" into the Background Program field. That will
706 cause gdm to run xscreensaver while nobody is logged in, and kill it as
707 soon as someone does log in. (The user will then be responsible for
708 starting xscreensaver on their own, if they want.)
709 Another way to accomplish the same thing is to edit the file
711 /etc/X11/gdm/gdm.conf to include:
712 BackgroundProgram=xscreensaver -nosplash
713 RunBackgroundProgramAlways=true
714 In this situation, the xscreensaver process will probably be running as
715 user gdm instead of root. You can configure the settings for this
716 nobody-logged-in state (timeouts, DPMS, etc.) by editing the
717 ~gdm/.xscreensaver file.
718 To get gdm to run the BackgroundProgram, you may need to switch it from
720 the "Graphical Greeter" to the "Standard Greeter".
721
723 I understand that KDE has invented their own wrapper around xscreen‐
724 saver, that is inferior to xscreensaver-demo(1) in any number of ways.
725 I've never actually seen it, but I'm told that this is the way you dis‐
726 able it:
727 1: Switch off KDE's screen saver.
729 Open the ``Control Center'' and select the ``Appearance & Themes
730 -> Screensaver'' page. Turn off the ``Start Automatically''
731 checkbox.
732 2: Find your Autostart directory.
734 Open the ``System Administration -> Paths'' page, and see what
735 your ``Autostart path'' is set to: it will probably be
736 ~/.kde/Autostart/ or something similar.
737 3: Make xscreensaver be an Autostart program.
739 Create a .desktop file in your autostart directory called
740 xscreensaver.desktop that contains the following five lines:
741 [Desktop Entry]
742 Exec=xscreensaver
743 Name=XScreensaver
744 Type=Application
745 X-KDE-StartupNotify=false
746 4: Make the various "lock session" buttons call xscreensaver.
748 Replace the file /usr/bin/kdesktop_lock (or possibly
749 /usr/kde/3.5/bin/kdesktop_lock) with these two lines:
750 #!/bin/sh
751 xscreensaver-command -lock
752 Make sure the file is executable (chmod a+x).
753 Now use xscreensaver normally, controlling it via the usual xscreen‐
755 saver-demo(1) and xscreensaver-command(1) mechanisms.
756
758 The easiest way to use xscreensaver on a system with CDE is to simply
759 switch off the built-in CDE screensaver, and use xscreensaver instead;
760 and second, to tell the front panel to run xscreensaver-command(1) with
761 the -lock option when the Lock icon is clicked.
762 To accomplish this involves five steps:
764 1: Switch off CDE's locker
766 Do this by turning off ``Screen Saver and Screen Lock'' in the
767 Screen section of the Style Manager.
768 2: Edit sessionetc
770 Edit the file ~/.dt/sessions/sessionetc and add to it the line
771 xscreensaver &
772 And make sure the sessionetc file is executable. This will
773 cause xscreensaver to be launched when you log in. (As always,
774 make sure that xscreensaver and the graphics demos are on your
775 $PATH; the path needs to be set in .cshrc and/or .dtprofile, not
776 .login.)
777 3: Create XScreenSaver.dt
779 Create a file called ~/.dt/types/XScreenSaver.dt with the fol‐
780 lowing contents:
781 ACTION XScreenSaver
782 {
783 LABEL XScreenSaver
784 TYPE COMMAND
785 EXEC_STRING xscreensaver-command -lock
786 ICON Dtkey
787 WINDOW_TYPE NO_STDIO
788 }
789 This defines a ``lock'' command for the CDE front panel, that
790 knows how to talk to xscreensaver.
791 4: Create Lock.fp
793 Create a file called ~/.dt/types/Lock.fp with the following con‐
794 tents:
795 CONTROL Lock
796 {
797 TYPE icon
798 CONTAINER_NAME Switch
799 CONTAINER_TYPE SWITCH
800 POSITION_HINTS 1
801 ICON Fplock
802 LABEL Lock
803 PUSH_ACTION XScreenSaver
804 HELP_TOPIC FPOnItemLock
805 HELP_VOLUME FPanel
806 }
807 This associates the CDE front panel ``Lock'' icon with the lock
808 command we just defined in step 3.
809 5: Restart
811 Select ``Restart Workspace Manager'' from the popup menu to make
812 your changes take effect. If things seem not to be working,
813 check the file ~/.dt/errorlog for error messages.
814
816 Since CDE is a descendant of VUE, the instructions for using xscreen‐
817 saver under VUE are similar to the above:
818 1: Switch off VUE's locker
820 Open the ``Style Manager'' and select ``Screen.'' Turn off
821 ``Screen Saver and Screen Lock'' option.
822 2: Make sure you have a Session
824 Next, go to the Style Manager's, ``Startup'' page. Click on
825 ``Set Home Session'' to create a session, then on ``Return to
826 Home Session'' to select this session each time you log in.
827 3: Edit vue.session
829 Edit the file ~/.vue/sessions/home/vue.session and add to it the
830 line
831 vuesmcmd -screen 0 -cmd "xscreensaver"
832 This will cause xscreensaver to be launched when you log in.
833 (As always, make sure that xscreensaver and the graphics demos
834 are on your $PATH; the path needs to be set in .cshrc and/or
835 .profile, not .login.)
836 3: Edit vuewmrc
838 Edit the file ~/.vue/vuewmrc and add (or change) the Lock con‐
839 trol:
840 CONTROL Lock
841 {
842 TYPE button
843 IMAGE lock
844 PUSH_ACTION f.exec "xscreensaver-command -lock"
845 HELP_TOPIC FPLock
846 }
847 This associates the VUE front panel ``Lock'' icon with the
848 xscreensaver lock command.
849
851 Bugs? There are no bugs. Ok, well, maybe. If you find one, please
852 let me know. http://www.jwz.org/xscreensaver/bugs.html explains how to
853 construct the most useful bug reports.
854 Locking and XDM
856 If xscreensaver has been launched from xdm(1) before anyone has
857 logged in, you will need to kill and then restart the xscreen‐
858 saver daemon after you have logged in, or you will be confused
859 by the results. (For example, locking won't work, and your
860 ~/.xscreensaver file will be ignored.)
861 When you are logged in, you want the xscreensaver daemon to be
863 running under your user id, not as root or some other user.
864 If it has already been started by xdm, you can kill it by send‐
866 ing it the exit command, and then re-launching it as you, by
867 putting something like the following in your personal X startup
868 script:
869 xscreensaver-command -exit
870 xscreensaver &
871 The ``Using XDM(1)'' section, above, goes into more detail, and
872 explains how to configure the system to do this for all users
873 automatically.
874 Locking and root logins
876 In order for it to be safe for xscreensaver to be launched by
877 xdm, certain precautions had to be taken, among them that
878 xscreensaver never runs as root. In particular, if it is
879 launched as root (as xdm is likely to do), xscreensaver will
880 disavow its privileges, and switch itself to a safe user id
881 (such as nobody.)
882 An implication of this is that if you log in as root on the
884 console, xscreensaver will refuse to lock the screen (because
885 it can't tell the difference between root being logged in on
886 the console, and a normal user being logged in on the console
887 but xscreensaver having been launched by the xdm(1) Xsetup
888 file.)
889 The solution to this is simple: you shouldn't be logging in on
891 the console as root in the first place! (What, are you crazy
892 or something?)
893 Proper Unix hygiene dictates that you should log in as your‐
895 self, and su(1) to root as necessary. People who spend their
896 day logged in as root are just begging for disaster.
897 XAUTH and XDM
899 For xscreensaver to work when launched by xdm(1), programs run‐
900 ning on the local machine as user "nobody" must be able to con‐
901 nect to the X server. This means that if you want to run
902 xscreensaver on the console while nobody is logged in, you may
903 need to disable cookie-based access control (and allow all
904 users who can log in to the local machine to connect to the
905 display.)
906 You should be sure that this is an acceptable thing to do in
908 your environment before doing it. See the ``Using XDM(1)''
909 section, above, for more details.
910 Passwords
912 If you get an error message at startup like ``couldn't get
913 password of user'' then this probably means that you're on a
914 system in which the getpwent(3) library routine can only be
915 effectively used by root. If this is the case, then xscreen‐
916 saver must be installed as setuid to root in order for locking
917 to work. Care has been taken to make this a safe thing to do.
918 It also may mean that your system uses shadow passwords instead
920 of the standard getpwent(3) interface; in that case, you may
921 need to change some options with configure and recompile.
922 If you change your password after xscreensaver has been
924 launched, it will continue using your old password to unlock
925 the screen until xscreensaver is restarted. On some systems,
926 it may accept both your old and new passwords. So, after you
927 change your password, you'll have to do
928 xscreensaver-command -restart
929 to make xscreensaver notice.
930 PAM Passwords
932 If your system uses PAM (Pluggable Authentication Modules),
933 then in order for xscreensaver to use PAM properly, PAM must be
934 told about xscreensaver. The xscreensaver installation process
935 should update the PAM data (on Linux, by creating the file
936 /etc/pam.d/xscreensaver for you, and on Solaris, by telling you
937 what lines to add to the /etc/pam.conf file.)
938 If the PAM configuration files do not know about xscreensaver,
940 then you might be in a situation where xscreensaver will refuse
941 to ever unlock the screen.
942 This is a design flaw in PAM (there is no way for a client to
944 tell the difference between PAM responding ``I have never heard
945 of your module,'' and responding, ``you typed the wrong pass‐
946 word.'') As far as I can tell, there is no way for xscreen‐
947 saver to automatically work around this, or detect the problem
948 in advance, so if you have PAM, make sure it is configured cor‐
949 rectly!
950 Colormap lossage: TWM
952 The installColormap option doesn't work very well with the
953 twm(1) window manager and its descendants, on 8-bit screens.
954 There is a race condition between the screensaver and this win‐
956 dow manager, which can result in the screensaver's colormap not
957 getting installed properly, meaning the graphics hacks will
958 appear in essentially random colors. (If the screen goes white
959 instead of black, this is probably why.)
960 The mwm(1) and olwm(1) window managers don't have this problem.
962 The race condition exists because X (really, ICCCM) does not
963 provide a way for an OverrideRedirect window to have its own
964 colormap, short of grabbing the server (which is neither a good
965 idea, nor really possible with the current design.) What hap‐
966 pens is that, as soon as xscreensaver installs its colormap,
967 twm responds to the resultant ColormapNotify event by re-
968 installing the default colormap. Apparently, twm doesn't
969 always do this; it seems to do it regularly if the screensaver
970 is activated from a menu item, but seems to not do it if the
971 screensaver comes on of its own volition, or is activated from
972 another console.
973 Attention, window manager authors!
975 You should only call XInstallColormap(3) in response to
976 user events. That is, it is appropriate to install a col‐
977 ormap in response to FocusIn, FocusOut, EnterNotify, and
978 LeaveNotify events; but it is not appropriate to call it in
979 response to ColormapNotify events. If you install col‐
980 ormaps in response to application actions as well as in
981 response to user actions, then you create the situation
982 where it is impossible for override-redirect applications
983 (such as xscreensaver) to display their windows in the
984 proper colors.
985 Colormap lossage: XV, XAnim, XEarth
987 Some programs don't operate properly on visuals other than the
988 default one, or with colormaps other than the default one. See
989 the discussion of the magic "default-n" visual name in the
990 description of the programs resource in the Configuration sec‐
991 tion. When programs only work with the default colormap, you
992 need to use a syntax like this:
993 default-n: xv -root image-1.gif -quit \n\
994 default-n: xearth -nostars -wait 0 \n\
995 It would also work to turn off the installColormap option alto‐
996 gether, but that would deny extra colors to those programs that
997 can take advantage of them.
998 Machine Load
1000 Although this program ``nices'' the subprocesses that it
1001 starts, graphics-intensive subprograms can still overload the
1002 machine by causing the X server process itself (which is not
1003 ``niced'') to consume many cycles. Care has been taken in all
1004 the modules shipped with xscreensaver to sleep periodically,
1005 and not run full tilt, so as not to cause appreciable load.
1006 However, if you are running the OpenGL-based screen savers on a
1008 machine that does not have a video card with 3D acceleration,
1009 they will make your machine slow, despite nice(1).
1010 Your options are: don't use the OpenGL display modes; or, col‐
1012 lect the spare change hidden under the cushions of your couch,
1013 and use it to buy a video card manufactured after 1998. (It
1014 doesn't even need to be fast 3D hardware: the problem will be
1015 fixed if there is any 3D hardware at all.)
1016 XFree86's Magic Keystrokes
1018 The XFree86 X server traps certain magic keystrokes before
1019 client programs ever see them. Two that are of note are
1020 Ctrl+Alt+Backspace, which causes the X server to exit; and
1021 Ctrl+Alt+Fn, which switches virtual consoles. The X server
1022 will respond to these keystrokes even if xscreensaver has the
1023 screen locked. Depending on your setup, you might consider
1024 this a problem.
1025 Unfortunately, there is no way for xscreensaver itself to over‐
1027 ride the interpretation of these keys. If you want to disable
1028 Ctrl+Alt+Backspace globally, you need to set the DontZap flag
1029 in your /etc/X11/XF86Config file. To globally disable VT
1030 switching, you can set the DontVTSwitch flag. See the XF86Con‐
1031 fig(5) manual for details.
1032 MIT Extension and Fading
1034 The MIT-SCREEN-SAVER extension is junk. Don't use it.
1035 When using the MIT-SCREEN-SAVER extension in conjunction with
1037 the fade option, you'll notice an unattractive flicker just
1038 before the fade begins. This is because the server maps a
1039 black window just before it tells the xscreensaver process to
1040 activate. The xscreensaver process immediately unmaps that
1041 window, but this results in a flicker. I haven't figured a way
1042 to get around this; it seems to be a fundamental property of
1043 the (mis-) design of this server extension.
1044 It sure would be nice if someone would implement the SGI
1046 SCREEN_SAVER extension in XFree86; it's dead simple, and works
1047 far better than the over-engineered and broken MIT-SCREEN-SAVER
1048 extension.
1049 Keyboard LEDs
1051 If procInterrupts is on (which is the default on Linux systems)
1052 and you're using some program that toggles the state of your
1053 keyboard LEDs, xscreensaver won't work right: turning those
1054 LEDs on or off causes a keyboard interrupt, which xscreensaver
1055 will interpret as user activity. So if you're using such a
1056 program, set the procInterrupts resource to False.
1057 Extensions
1059 If you are not making use of one of the server extensions
1060 (XIDLE, SGI SCREEN_SAVER, or MIT-SCREEN-SAVER), then it is pos‐
1061 sible, in rare situations, for xscreensaver to interfere with
1062 event propagation and make another X program malfunction. For
1063 this to occur, that other application would need to not select
1064 KeyPress events on its non-leaf windows within the first 30
1065 seconds of their existence, but then select for them later. In
1066 this case, that client might fail to receive those events.
1067 This isn't very likely, since programs generally select a con‐
1068 stant set of events immediately after creating their windows
1069 and then don't change them, but this is the reason that it's a
1070 good idea to install and use one of the server extensions
1071 instead, to work around this shortcoming in the X protocol.
1072 In all these years, I've not heard of even a single case of
1074 this happening, but it is theoretically possible, so I'm men‐
1075 tioning it for completeness...
1076
1078 DISPLAY to get the default host and display number, and to inform the
1079 sub-programs of the screen on which to draw.
1080 PATH to find the sub-programs to run.
1082 HOME for the directory in which to read the .xscreensaver file.
1084 XENVIRONMENT
1086 to get the name of a resource file that overrides the global
1087 resources stored in the RESOURCE_MANAGER property.
1088
1090 The latest version of xscreensaver, an online version of this manual,
1091 and a FAQ can always be found at http://www.jwz.org/xscreensaver/
1092
1094 X(1), Xsecurity(1), xauth(1), xdm(1), gdm(1), xhost(1), xscreen‐
1095 saver-demo(1), xscreensaver-command(1), xscreensaver-gl-helper(1),
1096 xscreensaver-getimage(1), xscreensaver-text(1).
1097
1099 Copyright © 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
1100 2001, 2002, 2003, 2004, 2005 by Jamie Zawinski. Permission to use,
1101 copy, modify, distribute, and sell this software and its documentation
1102 for any purpose is hereby granted without fee, provided that the above
1103 copyright notice appear in all copies and that both that copyright
1104 notice and this permission notice appear in supporting documentation.
1105 No representations are made about the suitability of this software for
1106 any purpose. It is provided "as is" without express or implied war‐
1107 ranty.
1108
1110 Jamie Zawinski <jwz@jwz.org>. Written in late 1991; version 1.0 posted
1111 to comp.sources.x on 17-Aug-1992.
1112 Please let me know if you find any bugs or make any improvements.
1114
1116 Thanks to Angela Goodman for the XScreenSaver logo.
1117 Thanks to the many people who have contributed graphics demos to the
1119 package.
1120 Thanks to David Wojtowicz for implementing lockTimeout.
1122 Thanks to Martin Kraemer for adding support for shadow passwords and
1124 locking-disabled diagnostics.
1125 Thanks to Patrick Moreau for the VMS port.
1127 Thanks to Nat Lanza for the Kerberos support.
1129 Thanks to Bill Nottingham for the initial PAM support.
1131 And thanks to Jon A. Christopher for implementing the Athena dialog
1133 support, back in the days before Lesstif or Gtk were viable alterna‐
1134 tives to Motif.
1135X Version 11 5.05-3 (06-Apr-2008) xscreensaver(1)