1XScreenSaver(1) General Commands Manual XScreenSaver(1)
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3
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6 xscreensaver - extensible screen saver and screen locking framework
7
9 xscreensaver [--display host:display.screen] [--verbose] [--version]
10 [--no-splash] [--log filename]
11
13 XScreenSaver waits until the user is idle, and then runs graphics demos
14 chosen at random. It can also lock your screen, and provides configu‐
15 ration and control of display power management.
16
17 XScreenSaver is also available on macOS, iOS and Android.
18
20 XScreenSaver is a daemon that runs in the background. You configure it
21 with the xscreensaver-settings(1) program.
22
23 xscreensaver &
24 xscreensaver-settings
25
26
28 When it is time to activate the screensaver, a full-screen black window
29 is created that covers each monitor. A sub-process is launched for
30 each one running a graphics demo, pointed at the appropriate window.
31 Because of this, any program which can draw on a provided window can be
32 used as a screensaver. The various graphics demos are, in fact, just
33 standalone programs that do that.
34
35 When the user becomes active again, the screensaver windows are un‐
36 mapped, and the running subprocesses are killed.
37
38 The display modes are run at a low process priority, and spend most of
39 their time sleeping/idle by default, so they should not consume signif‐
40 icant system resources.
41
43 --display host:display.screen
44 The X display to use. For displays with multiple screens,
45 XScreenSaver will manage all screens on the display simultane‐
46 ously.
47
48 --verbose
49 Print diagnostics to stderr.
50
51 --version
52 Print the version number and exit.
53
54 --log filename
55 Append all diagnostic output to the given file. This also im‐
56 plies --verbose. Use this when reporting bugs.
57
58 --no-splash
59 Don't display the splash screen at startup.
60
62 The xscreensaver-settings(1) program is where you configure if and when
63 your monitor should power off. It saves the settings in your
64 ~/.xscreensaver file. Do not use xset(1) to manually change the power
65 management settings, that won't work.
66
67 When the monitor is powered down, the display hacks will stop running
68 (though it may take a minute or two for XScreenSaver to notice).
69
71 If your system uses systemd(1) or elogind(8), then closing the lid of
72 your laptop will cause the screen to lock immediately.
73
74 If not, then the screen might not lock until a few seconds after you
75 re-open the lid. Which is less than ideal. So if you do not have sys‐
76 temd(1), you might want to get in the habit of manually locking your
77 screen before closing the lid (xscreensaver-command --lock).
78
80 Likewise, if you have systemd(1) or elogind(8), then all of the popular
81 video players and web browsers will prevent XScreenSaver from blanking
82 the screen while video is playing.
83
84 Both of these features require that xscreensaver-systemd(6) be able
85 connect to D-Bus.
86
88 Each desktop environment has its own system for launching long-running
89 daemons like XScreenSaver, and since many of them come bundled with
90 their own (buggy, insecure, inferior) screen-locking frameworks, it is
91 also necessary to disable those other frameworks before XScreenSaver
92 can work.
93
94 INSTALLING XSCREENSAVER ON GNOME OR UNITY
95 For many years, GNOME included XScreenSaver as-is, and everything just
96 worked. Not any more!
97
98 1: Fully uninstall the other screen saver packages:
99
100 sudo apt remove gnome-screensaver
101 sudo apt remove mate-screensaver
102 sudo apt remove cinnamon-screensaver
103 sudo apt remove light-locker
104 or
105 sudo rpm -e gnome-screensaver
106 sudo rpm -e mate-screensaver
107 sudo rpm -e cinnamon-screensaver
108 sudo rpm -e light-locker
109
110 Be careful that it doesn't try to uninstall all of GNOME.
111
112 2: Turn off GNOME's built-in blanking.
113 Set all of the following settings to "Never" or "Off", as these
114 are all controlled by xscreensaver-settings(1) now:
115
116 "Settings / Privacy / Screen Lock / Blank Screen Delay"
117 "Settings / Privacy / Screen Lock / Automatic Screen Lock"
118 "Settings / Power / Blank Screen"
119 "Settings / Power / Automatic Suspend"
120
121 3: Launch XScreenSaver at login.
122 Launch "Tweaks", select "Startup Applications", click the plus
123 sign, and select "XScreenSaver" (not "XScreenSaver Settings")
124 from the (very long) menu.
125
126 Or, see the "LAUNCHING XSCREENSAVER FROM SYSTEMD" section below.
127 That works too.
128
129 4: Make GNOME's "Lock" icon use XScreenSaver.
130 This used to work, but no longer does with GNOME 3.38. If you
131 figure it out, let me know! This still works for Cinnamon 4.8
132 and MATE 1.24:
133
134 sudo ln -sf /usr/bin/xscreensaver-command \
135 /usr/bin/gnome-screensaver-command
136 sudo ln -sf /usr/bin/xscreensaver-command \
137 /usr/bin/cinnamon-screensaver-command
138 sudo ln -sf /usr/bin/xscreensaver-command \
139 /usr/bin/mate-screensaver-command
140 sudo ln -sf /usr/bin/xscreensaver-command \
141 /usr/bin/xfce4-screensaver-command
142 sudo ln -sf /usr/bin/xscreensaver-command \
143 /usr/bin/light-locker-command
144
145 This change will get blown away when you upgrade.
146
147 INSTALLING XSCREENSAVER ON KDE
148 Like GNOME, KDE also decided to re-invent the wheel. To replace the
149 KDE screen saver with XScreenSaver, do the following:
150
151 1: Turn off KDE's built-in blanking.
152 In System Settings, un-check the following items, as these are
153 controlled by xscreensaver-settings(1) now:
154
155 "Workspace Behavior / Screen Locking / Lock automatically"
156 "Workspace Behavior / Screen Locking / After waking from sleep"
157 "Workspace Behavior / Screen Locking / Keyboard shortcut"
158 "Hardware / Power Management / Screen Energy Saving"
159 "Hardware / Power Management / Suspend session"
160 "Hardware / Power Management / Laptop lid closed" = Do Nothing
161
162 If there are multiple tabs, you may need to change these set‐
163 tings on all three of them: "On AC power", "Battery" and "Low
164 Battery".
165
166 2: Launch XScreenSaver at login.
167 Copy the file /usr/share/applications/xscreensaver.desktop into
168 the directory ~/.config/autostart/
169
170 3: Make KDE's "Lock" icon use XScreenSaver.
171 Find the "kscreenlocker_greet" program. It might be in
172 "/usr/lib/*/libexec/", or it might be somewhere else. Delete
173 that file and replace it with a file containing these two lines.
174 Make it executable (chmod a+x).
175
176 #!/bin/sh
177 xscreensaver-command --lock &
178
179 This change will get blown away when you upgrade.
180
181 4: Turn off KDE's built-in locking on suspend, even harder.
182 Even after disabling KDE's screen locking, above, it is possible
183 that KDE will still use its built-in locker when you close your
184 laptop's lid. If that is happening, double-check the settings
185 above, but if those are correct, try the following. First, en‐
186 sure you are running KDE 5.21 or newer. Next, enable "systemd
187 user sessions" for KDE so that you can edit the parameters for
188 ksmserver:
189
190 kwriteconfig5 --file startkderc --group General \
191 --key systemdBoot true
192
193 Log out and back in.
194
195 Next, edit the plasma-ksmserver service to change how ksmserver
196 is launched:
197
198 systemctl edit --user plasma-ksmserver.service
199
200 Replace the contents of the file that lets you edit with this:
201
202 [Service]
203 ExecStart=
204 ExecStart=/usr/bin/ksmserver --no-lockscreen
205
206 Then log out and back in again.
207
208 LAUNCHING XSCREENSAVER FROM LXDE
209 Add the line @xscreensaver to /etc/xdg/lxsession/LXDE/autostart or
210 /etc/xdg/lxsession/LXDE-pi/autostart.
211
212 LAUNCHING XSCREENSAVER FROM SYSTEMD
213 If you are not using GNOME, KDE or LXDE, the way to launch XScreenSaver
214 at login is probably systemd(1).
215
216 Copy the file /usr/share/xscreensaver/xscreensaver.service into the di‐
217 rectory ~/.config/systemd/user/. Create that directory first if it
218 doesn't exist. Then enable it with:
219
220 systemctl --user enable xscreensaver
221
222
223 LAUNCHING XSCREENAVER FROM UPSTART
224 If you are not using GNOME, KDE or LXDE, and your system uses up‐
225 start(7) instead of systemd(1), launch the "Startup Applications" ap‐
226 plet, click "Add", and enter these lines:
227
228 Name: XScreenSaver
229 Command: xscreensaver
230 Comment: XScreenSaver
231
232
233 LAPTOP LIDS WITHOUT SYSTEMD
234 BSD systems or other systems without systemd(1) or elogind(8) might
235 have luck by adding "xscreensaver-command --suspend" to some appropri‐
236 ate spot in /etc/acpi/events/anything or in /etc/acpi/handler.sh, if
237 those files exist.
238
239 LAUNCHING XSCREENSAVER FROM GDM
240 You can run xscreensaver from your gdm(1) session, so that the screen‐
241 saver will run even when nobody is logged in on the console. To do
242 this, run gdmconfig(1).
243
244 On the General page set the Local Greeter to Standard Greeter.
245
246 On the Background page, type the command "xscreensaver --no-splash"
247 into the Background Program field. That will cause gdm to run XScreen‐
248 Saver while nobody is logged in, and kill it as soon as someone does
249 log in. (The user will then be responsible for starting XScreenSaver
250 on their own, if they want.)
251
252 If that doesn't work, you can edit the config file directly. Edit
253 /etc/X11/gdm/gdm.conf to include:
254
255 Greeter=/usr/bin/gdmlogin
256 BackgroundProgram=xscreensaver --no-splash
257 RunBackgroundProgramAlways=true
258
259 In this situation, the xscreensaver process will be running as user
260 gdm. You can configure the settings for this nobody-logged-in state
261 (timeouts, DPMS, etc.) by editing the ~gdm/.xscreensaver file.
262
263 If you get "connection refused" errors when running xscreensaver from
264 gdm, then this probably means that you are having xauth(1) problems.
265 For information on the X server's access control mechanisms, see the
266 man pages for X(1), Xsecurity(1), xauth(1), and xhost(1).
267
268 There might be a way to accomplish this with other display managers.
269 It's a mystery!
270
272 Wayland is a completely different window system that is intended to re‐
273 place X11. After 14+ years of trying, some Linux distros have finally
274 begun enabling it by default. Most deployments of it also include
275 XWayland, which is a compatibility layer that allows some X11 programs
276 to continue to work within a Wayland environment.
277
278 Unfortunately, XScreenSaver is not one of those programs.
279
280 If your system is running XWayland, XScreenSaver will malfunction in
281 two ways:
282
283 1: It will be unable to detect user activity in non-X11 programs.
284
285 This means that while a native Wayland program is selected, XScreen‐
286 Saver will think that you are idle, and may blank the screen prema‐
287 turely.
288
289 2: It will be unable to lock the screen.
290
291 This is because X11 grabs don't work properly under XWayland, so
292 there is no way for XScreenSaver to prevent the user from switching
293 away from the screen locker to another application.
294
295 In short, for XScreenSaver to work properly, you will need to switch
296 off Wayland and use the X Window System like in the "good old days".
297
298 TO DISABLE WAYLAND UNDER GNOME
299 The login screen should have a gear-icon menu that lets you change the
300 session type from "GNOME" (the Wayland session) to "GNOME on Xorg" (the
301 X11 session).
302
303 Alternately, edit /etc/gdm/custom.conf and make sure it includes this
304 line:
305
306 WaylandEnable=false
307
308 TO DISABLE WAYLAND UNDER KDE
309 The login screen should have a menu that lets you change the session
310 type to "Plasma (X11)".
311
312 Alternately, edit /etc/sddm.conf and change the SessionDir line under
313 the [Wayland] section to say:
314
315 SessionDir=/dev/null
316
318 XScreenSaver has a decades-long track record of securely locking your
319 screen. However, there are many things that can go wrong. X11 is a
320 very old system, and has a number of design flaws that make it suscep‐
321 tible to foot-shooting.
322
323 MAGIC BACKDOOR KEYSTROKES
324 The Xorg and XFree86 X servers, as well as the Linux kernel, both trap
325 certain magic keystrokes before X11 client programs ever see them. If
326 you care about keeping your screen locked, this is a big problem.
327
328 Ctrl+Alt+Backspace
329 This keystroke kills the X server, and on some systems, leaves you
330 at a text console. If the user launched X11 manually, that text
331 console will still be logged in. To disable this keystroke globally
332 and permanently, you need to set the DontZap flag in your
333 xorg.conf(5) or XF86Config(5) file.
334
335 Ctrl-Alt-F1, Ctrl-Alt-F2, etc.
336 These keystrokes will switch to a different virtual console, while
337 leaving the console that X11 is running on locked. If you left a
338 shell logged in on another virtual console, it is unprotected. So
339 don't leave yourself logged in on other consoles. You can disable
340 VT switching globally and permanently by setting DontVTSwitch in
341 your xorg.conf(5), but that might make your system harder to use,
342 since VT switching is an actual useful feature.
343
344 There is no way to disable VT switching only when the screen is
345 locked. It's all or nothing.
346
347 Ctrl-Alt-KP_Multiply
348 This keystroke kills any X11 app that holds a lock, so typing this
349 will kill XScreenSaver and unlock the screen. You can disable it by
350 turning off AllowClosedownGrabs in xorg.conf(5).
351
352 Alt-SysRq-F
353 This is the Linux kernel "OOM-killer" keystroke. It shoots down
354 random long-running programs of its choosing, and so might target
355 and kill XScreenSaver. You can disable this keystroke globally
356 with:
357
358 echo 176 > /proc/sys/kernel/sysrq
359
360 There's little that I can do to make the screen locker be secure so
361 long as the kernel and X11 developers are actively working against
362 security like this. The strength of the lock on your front door
363 doesn't matter much so long as someone else in the house insists on
364 leaving a key under the welcome mat.
365
366 THE OOM-KILLER
367 Even if you have disabled the Alt-SysRq-F OOM-killer keystroke, the
368 OOM-killer might still decide to assassinate XScreenSaver at random,
369 which will unlock your screen. If the xscreensaver-auth(6) program is
370 installed setuid, it attempts to tell the OOM-killer to leave the
371 XScreenSaver daemon alone, but that may or may not work.
372
373 You would think that the OOM-killer would pick the process using the
374 most memory, but most of the time it seems to pick the process that
375 would be most comically inconvenient, such as your screen locker, or
376 crond(8). You can disable the OOM-killer entirely with:
377
378 echo 2 > /proc/sys/vm/overcommit_memory
379 echo vm.overcommit_memory = 2 >> /etc/sysctl.conf
380
381 In addition to the kernel's OOM-killer, systemd(1) has its own. The
382 included xscreensaver.service file attempts to evade it, but you may
383 want to just turn it off anyway:
384
385 sudo systemctl disable --now systemd-oomd
386 sudo systemctl mask systemd-oomd
387
388
389 X SERVER ACCESS IS GAME OVER
390 X11's security model is all-or-nothing. If a program can connect to
391 your X server at all, either locally or over the network, it can log
392 all of your keystrokes, simulate keystrokes, launch arbitrary programs,
393 and change the settings of other programs. Assume that anything that
394 can connect to your X server can execute arbitrary code as the logged-
395 in user. See Xsecurity(1) and xauth(1).
396
397 PAM PASSWORDS
398 If your system uses PAM (Pluggable Authentication Modules), then PAM
399 must be configured for XScreenSaver. If it is not, then you might be
400 in a situation where you can't unlock. Probably the file you need is
401 /etc/pam.d/xscreensaver.
402
403 DON'T LOG IN AS ROOT
404 Never log in as root. Log in as a normal user and use sudo(1) as nec‐
405 essary. If you are logged in as root, XScreenSaver will not lock your
406 screen or run display modes, for numerous good and proper reasons.
407
409 For a single user, the proper way to configure XScreenSaver is to sim‐
410 ply run the xscreensaver-settings(1) program, and change the settings
411 through the GUI. Changes are written to the ~/.xscreensaver file.
412
413 If you want to set the system-wide defaults, then make your edits to
414 /etc/X11/app-defaults/XScreenSaver instead. The two files have similar
415 (but not identical) syntax.
416
417 You can also make changes via the X Resource Database and xrdb(1), but
418 that can be very confusing and is not really recommended.
419
420 Options in ~/.xscreensaver override any settings in the resource data‐
421 base or app-defaults file.
422
423 If you change a setting in the .xscreensaver file while XScreenSaver is
424 already running, it will notice this, and reload the file as needed.
425 But if you change a setting in the X Resource Database, you will need
426 to restart XScreenSaver for those changes to take effect:
427
428 xrdb < ~/.Xdefaults
429 xscreensaver-command --restart
430
431
433 These are the X resources use by XScreenSaver program. You probably
434 won't need to change these manually: that's what the xscreensaver-set‐
435 tings(1) program is for.
436
437 timeout (class Time)
438 The screensaver will activate (blank the screen) after the key‐
439 board and mouse have been idle for this many minutes. Default
440 10 minutes.
441
442 cycle (class Time)
443 After the screensaver has been running for this many minutes,
444 the currently running graphics-hack sub-process will be killed
445 (with SIGTERM), and a new one started. If this is 0, then the
446 graphics hack will never be changed: only one demo will run un‐
447 til the screensaver is deactivated by user activity. Default
448 10 minutes.
449
450 If there are multiple screens, the savers are staggered
451 slightly so that while they all change every cycle minutes,
452 they don't all change at the same time.
453
454 lock (class Boolean)
455 Enable locking: before the screensaver will turn off, it will
456 require you to type the password of the logged-in user.
457
458 lockTimeout (class Time)
459 If locking is enabled, this controls the length of the "grace
460 period" between when the screensaver activates, and when the
461 screen becomes locked. For example, if this is 5, and timeout
462 is 10, then after 10 minutes, the screen would blank. If there
463 was user activity at 12 minutes, no password would be required
464 to un-blank the screen. But, if there was user activity at 15
465 minutes or later (that is, lockTimeout minutes after activa‐
466 tion) then a password would be required. The default is 0,
467 meaning that if locking is enabled, then a password will be re‐
468 quired as soon as the screen blanks.
469
470 passwdTimeout (class Time)
471 If the screen is locked, then this is how many seconds the
472 password dialog box should be left on the screen before giving
473 up (default 30 seconds). A few seconds are added each time you
474 type a character.
475
476 dpmsEnabled (class Boolean)
477 Whether power management is enabled.
478
479 dpmsStandby (class Time)
480 If power management is enabled, how long until the monitor goes
481 solid black.
482
483 dpmsSuspend (class Time)
484 If power management is enabled, how long until the monitor goes
485 into power-saving mode.
486
487 dpmsOff (class Time)
488 If power management is enabled, how long until the monitor pow‐
489 ers down completely. Note that these settings will have no ef‐
490 fect unless both the X server and the display hardware support
491 power management; not all do. See the Power Management sec‐
492 tion, below, for more information.
493
494 dpmsQuickOff (class Boolean)
495 If mode is blank and this is true, then the screen will be pow‐
496 ered down immediately upon blanking, regardless of other power-
497 management settings.
498
499 verbose (class Boolean)
500 Whether to print diagnostics. Default false.
501
502 splash (class Boolean)
503 Whether to display a splash screen at startup. Default true.
504
505 splashDuration (class Time)
506 How long the splash screen should remain visible; default 5
507 seconds.
508
509 helpURL (class URL)
510 The splash screen has a Help button on it. When you press it,
511 it will display the web page indicated here in your web
512 browser.
513
514 loadURL (class LoadURL)
515 This is the shell command used to load a URL into your web
516 browser.
517
518 demoCommand (class DemoCommand)
519 This is the shell command run when the Demo button on the
520 splash window is pressed. It defaults to xscreensaver-set‐
521 tings(1).
522
523 newLoginCommand (class NewLoginCommand)
524 If set, this is the shell command that is run when the "New Lo‐
525 gin" button is pressed on the unlock dialog box, in order to
526 create a new desktop session without logging out the user who
527 has locked the screen. Typically this will be some variant of
528 gdmflexiserver(1), kdmctl(1), lxdm(1) or dm-tool(1).
529
530 nice (class Nice)
531 The sub-processes launched by XScreenSaver will be "niced" to
532 this level, so that they are given lower priority than other
533 processes on the system, and don't increase the load unneces‐
534 sarily. The default is 10. (Higher numbers mean lower prior‐
535 ity; see nice(1) for details.)
536
537 fade (class Boolean)
538 If this is true, then when the screensaver activates, the desk‐
539 top will fade to black instead of simply winking out. Default:
540 true.
541
542 unfade (class Boolean)
543 If this is true, then when the screensaver deactivates, desktop
544 will fade back ininstead of appearing immediately. This is
545 only done if fade is true as well. Default: true.
546
547 fadeSeconds (class Time)
548 If fade is true, this is how long the fade will be in seconds.
549 Default 3 seconds.
550
551 ignoreUninstalledPrograms (class Boolean)
552 There may be programs in the list that are not installed on the
553 system, yet are marked as "enabled". If this preference is
554 true, then such programs will simply be ignored. If false,
555 then a warning will be printed if an attempt is made to run the
556 nonexistent program. Also, the xscreensaver-settings(1) pro‐
557 gram will suppress the non-existent programs from the list if
558 this is true. Default: false.
559
560 authWarningSlack (class Integer)
561 After you successfully unlock the screen, a dialog may pop up
562 informing you of previous failed login attempts. If all of
563 those login attemps were within this amount of time, they are
564 ignored. The assumption is that incorrect passwords entered
565 within a few seconds of a correct one are user error, rather
566 than hostile action. Default 20 seconds.
567
568 mode (class Mode)
569 Controls the screen-saving behavior. Valid values are:
570
571 random When blanking the screen, select a random display mode
572 from among those that are enabled and applicable. This
573 is the default.
574
575 random-same
576 Like random, but if there are multiple screens, each
577 screen will run the same random display mode, instead
578 of each screen running a different one.
579
580 one When blanking the screen, only ever use one particular
581 display mode (the one indicated by the selected set‐
582 ting).
583
584 blank When blanking the screen, just go black: don't run any
585 graphics hacks.
586
587 off Don't ever blank the screen, and don't ever allow the
588 monitor to power down.
589
590 selected (class Integer)
591 When mode is set to one, this is the one, indicated by its in‐
592 dex in the programs list. You're crazy if you count them and
593 set this number by hand: let xscreensaver-settings(1) do it for
594 you!
595
596 programs (class Programs)
597 The graphics hacks which XScreenSaver runs when the user is
598 idle. The value of this resource is a multi-line string, one
599 sh-syntax command per line. Each line must contain exactly one
600 command: no semicolons, no ampersands.
601
602 When the screensaver starts up, one of these is selected (ac‐
603 cording to the mode setting), and run. After the cycle period
604 expires, it is killed, and another is selected and run.
605
606 If a line begins with a dash (-) then that particular program
607 is disabled: it won't be selected at random (though you can
608 still select it explicitly using the xscreensaver-settings(1)
609 program).
610
611 If all programs are disabled, then the screen will just be made
612 blank, as when mode is set to blank.
613
614 To disable a program, you must mark it as disabled with a dash
615 instead of removing it from the list. This is because the sys‐
616 tem-wide (app-defaults) and per-user (.xscreensaver) settings
617 are merged together, and if a user just deletes an entry from
618 their programs list, but that entry still exists in the system-
619 wide list, then it will come back. However, if the user dis‐
620 ables it, then their setting takes precedence.
621
622 The default XScreenSaver hacks directory (typically
623 /usr/libexec/xscreensaver/) is prepended to $PATH before
624 searching for these programs.
625
626 To use a program as a screensaver, it must be able to render
627 onto the window provided to it in the $XSCREENSAVER_WINDOW en‐
628 vironment variable. If it creates and maps its own window in‐
629 stead, it won't work. It must render onto the provided window.
630
631 Visuals:
632
633 Because XScreenSaver was created back when dinosaurs roamed the
634 earth, it still contains support for some things you've proba‐
635 bly never seen, such as 1-bit monochrome monitors, grayscale
636 monitors, and monitors capable of displaying only 8-bit col‐
637 ormapped images.
638
639 If there are some programs that you want to run only when using
640 a color display, and others that you want to run only when us‐
641 ing a monochrome display, you can specify that like this:
642
643 mono: mono-program -root \n\
644 color: color-program -root \n\
645
646 More generally, you can specify the kind of visual that should
647 be used for the window on which the program will be drawing.
648 For example, if one program works best if it has a colormap,
649 but another works best if it has a 24-bit visual, both can be
650 accommodated:
651
652 PseudoColor: cmap-program -root \n\
653 TrueColor: 24bit-program -root \n\
654
655 In addition to the symbolic visual names described above (in
656 the discussion of the visualID resource) one other visual name
657 is supported in the programs list:
658
659 default-n
660 This is like default, but also requests the use of the default
661 colormap, instead of a private colormap.
662
663 If you specify a particular visual for a program, and that visual does
664 not exist on the screen, then that program will not be chosen to run.
665 This means that on displays with multiple screens of different depths,
666 you can arrange for appropriate hacks to be run on each. For example,
667 if one screen is color and the other is monochrome, hacks that look
668 good in mono can be run on one, and hacks that only look good in color
669 will show up on the other.
670
671 visualID (class VisualID)
672 This is an historical artifact left over from when 8-bit dis‐
673 plays were still common. You should probably ignore this.
674
675 Specify which X visual to use by default. (Note carefully that
676 this resource is called visualID, not merely visual; if you set
677 the visual resource instead, things will malfunction in obscure
678 ways for obscure reasons.)
679
680 Valid values for the VisualID resource are:
681
682 default Use the screen's default visual (the visual of the root
683 window). This is the default.
684
685 best Use the visual which supports the most colors. Note,
686 however, that the visual with the most colors might be
687 a TrueColor visual, which does not support colormap an‐
688 imation. Some programs have more interesting behavior
689 when run on PseudoColor visuals than on TrueColor.
690
691 mono Use a monochrome visual, if there is one.
692
693 gray Use a grayscale or staticgray visual, if there is one
694 and it has more than one plane (that is, it's not mono‐
695 chrome).
696
697 color Use the best of the color visuals, if there are any.
698
699 GL Use the visual that is best for OpenGL programs.
700 (OpenGL programs have somewhat different requirements
701 than other X programs.)
702
703 class where class is one of StaticGray, StaticColor, True‐
704 Color, GrayScale, PseudoColor, or DirectColor. Selects
705 the deepest visual of the given class.
706
707 N where number (decimal or hex) is interpreted as a vis‐
708 ual id number, as reported by the xdpyinfo(1) program;
709 in this way you can have finer control over exactly
710 which visual gets used, for example, to select a shal‐
711 lower one than would otherwise have been chosen.
712
713 Note that this option specifies only the default visual that
714 will be used: the visual used may be overridden on a program-
715 by-program basis. See the description of the programs re‐
716 source, above.
717
718 installColormap (class Boolean)
719 This is an historical artifact left over from when 8-bit dis‐
720 plays were still common. On PseudoColor (8-bit) displays, in‐
721 stall a private colormap while the screensaver is active, so
722 that the graphics hacks can get as many colors as possible.
723 This is the default. (This only applies when the screen's de‐
724 fault visual is being used, since non-default visuals get their
725 own colormaps automatically.) This can also be overridden on a
726 per-hack basis: see the discussion of the default-n name in the
727 section about the programs resource.
728
729 This does nothing if you have a TrueColor (16-bit or deeper)
730 display. (Which, in this century, you do.)
731
732 pointerHysteresis (class Integer)
733 If the mouse moves less than this-many pixels in a second, ig‐
734 nore it (do not consider that to be "activity"). This is so
735 that the screen doesn't un-blank (or fail to blank) just be‐
736 cause you bumped the desk. Default: 10 pixels.
737
738 A single pixel of motion will still cause the monitor to power
739 back on, but not un-blank. This is because the X11 server it‐
740 self unfortunately handles power-management-related activity
741 detection rather than XScreenSaver.
742
744 https://www.jwz.org/xscreensaver/bugs.html explains how to write the
745 most useful bug reports. If you find a bug, please let me know!
746
748 DISPLAY to get the default host and display number, and to inform the
749 sub-programs of the screen on which to draw.
750
751 XSCREENSAVER_WINDOW
752 Passed to sub-programs to indicate the ID of the window on
753 which they should draw.
754
755 PATH to find the sub-programs to run, including the display modes.
756
757 HOME for the directory in which to read the .xscreensaver file.
758
759 XENVIRONMENT
760 to get the name of a resource file that overrides the global
761 resources stored in the RESOURCE_MANAGER property.
762
764 The latest version of XScreenSaver, an online version of this manual,
765 and a FAQ can always be found at https://www.jwz.org/xscreensaver/
766
768 X(1), Xsecurity(1), xauth(1), xdm(1), gdm(1), xhost(1), systemd(1), el‐
769 ogind(8), xscreensaver-settings(1), xscreensaver-command(1), xscreen‐
770 saver-systemd(6), xscreensaver-gl-helper(6), xscreensaver-getimage(6),
771 xscreensaver-text(6).
772
774 Copyright © 1991-2022 by Jamie Zawinski. Permission to use, copy, mod‐
775 ify, distribute, and sell this software and its documentation for any
776 purpose is hereby granted without fee, provided that the above copy‐
777 right notice appear in all copies and that both that copyright notice
778 and this permission notice appear in supporting documentation. No rep‐
779 resentations are made about the suitability of this software for any
780 purpose. It is provided "as is" without express or implied warranty.
781
783 Jamie Zawinski <jwz@jwz.org>
784
785 Please let me know if you find any bugs or make any improvements.
786
787 And a huge thank you to the hundreds of people who have contributed, in
788 large ways and small, to the XScreenSaver collection over the past
789 three decades!
790
791
792
793X Version 11 6.08-1.fc38 (17-Oct-2023) XScreenSaver(1)