14 .TH XScreenSaver 1 "20-Jun-99 (3.15)" "X Version 11"
16 xscreensaver - graphics hack and screen locker, launched when the user is idle
19 [\-display \fIhost:display.screen\fP] \
20 [\-timeout \fIint\fP] \
24 [\-lock\-timeout \fIint\fP] \
25 [\-visual \fIvisual\fP] \
32 [\-no\-capture\-stderr] \
37 [\-no\-mit\-extension] \
39 [\-no\-sgi\-extension] \
40 [\-xidle\-extension] \
41 [\-no\-xidle\-extension] \
42 [\-proc\-interrupts] \
43 [\-no\-proc\-interrupts] \
44 [\-xrm \fIresources\fP]
46 The \fIxscreensaver\fP program waits until the keyboard and mouse have been
47 idle for a period, and then runs a graphics demo chosen at random. It
48 turns off as soon as there is any mouse or keyboard activity.
50 This program can lock your terminal in order to prevent others from using it,
51 though its default mode of operation is merely to display pretty pictures on
52 your screen when it is not in use.
54 The benefit that this program has over the combination of the
58 programs is the ease with which new graphics hacks can be installed. You
59 don't need to recompile (or even re-run) this program to add a new display
62 For the impatient, try this:
68 .BR xscreensaver-demo (1)
69 program should pop up a dialog box that lets you experiment with the
70 xscreensaver settings and graphics modes.
75 xscreensaver has a client-server model: the \fIxscreensaver\fP program is a
76 daemon that runs in the background; it is controlled by the foreground
77 .BR xscreensaver-demo (1)
79 .BR xscreensaver-command (1)
82 Options to \fIxscreensaver\fP are specified in one of two places: in
83 a \fI.xscreensaver\fP file in your home directory; or in the X resource
84 database. If the \fI.xscreensaver\fP file exists, it overrides any settings
85 in the resource database.
87 The syntax of the \fI.xscreensaver\fP file is similar to that of
88 the \fI.Xdefaults\fP file; for example, to set the \fItimeout\fP paramter
89 in the \fI.xscreensaver\fP file, you would write the following:
93 whereas, in the \fI.Xdefaults\fP file, you would write
95 xscreensaver.timeout: 5
97 If you change a setting in the \fI.xscreensaver\fP file while xscreensaver
98 is already running, it will notice this, and reload the file. (The file will
99 be reloaded the next time the screen saver needs to take some action, such as
100 blanking or unblanking the screen, or picking a new graphics mode.)
102 If you change a setting in your X resource database, or if you want
103 xscreensaver to notice your changes immediately instead of the next time
104 it wakes up, then you will need to tell the running xscreensaver process
105 to re-initialize itself, like so:
107 xscreensaver-command -restart
109 Note that if you changed the \fI.Xdefaults\fP file, you might also need to run
114 If you want to set the system-wide defaults, then make your edits to
115 the xscreensaver app-defaults file, which should have been installed
116 when xscreensaver itself was installed. The app-defaults file will
117 usually be named /usr/lib/X11/app-defaults/XScreenSaver, but different
118 systems might keep it in a different place (for example,
119 /usr/openwin/lib/app-defaults/XScreenSaver on Solaris.)
121 When settings are changed in the Preferences dialog box (see above)
122 the current settings will be written to the \fI.xscreensaver\fP file.
123 (The \fI.Xdefaults\fP file and the app-defaults file will never be
124 written by xscreensaver itself.)
127 .B timeout\fP (class \fBTime\fP)
128 The screensaver will activate (blank the screen) after the keyboard and
129 mouse have been idle for this many minutes. Default 10 minutes.
131 .B cycle\fP (class \fBTime\fP)
132 After the screensaver has been running for this many minutes, the currently
133 running graphics-hack sub-process will be killed (with \fBSIGTERM\fP), and a
134 new one started. If this is 0, then the graphics hack will never be changed:
135 only one demo will run until the screensaver is deactivated by user activity.
138 .B lock\fP (class \fBBoolean\fP)
139 Enable locking: before the screensaver will turn off, it will require you
140 to type the password of the logged-in user (really, the person who ran
141 xscreensaver), or the root password. (\fBNote:\fP this doesn't work if the
142 screensaver is launched by
144 because it can't know the user-id of the logged-in user. See
145 the ``\fIUsing XDM(1)\fP'' section, below.
147 .B lockTimeout\fP (class \fBTime\fP)
148 If locking is enabled, this controls the length of the ``grace period''
149 between when the screensaver activates, and when the screen becomes locked.
150 For example, if this is 5, and \fI\-timeout\fP is 10, then after 10 minutes,
151 the screen would blank. If there was user activity at 12 minutes, no password
152 would be required to un-blank the screen. But, if there was user activity
153 at 15 minutes or later (that is, \fI\-lock\-timeout\fP minutes after
154 activation) then a password would be required. The default is 0, meaning
155 that if locking is enabled, then a password will be required as soon as the
158 .B passwdTimeout\fP (class \fBTime\fP)
159 If the screen is locked, then this is how many seconds the password dialog box
160 should be left on the screen before giving up (default 30 seconds.) This
161 should not be too large: the X server is grabbed for the duration that the
162 password dialog box is up (for security purposes) and leaving the server
163 grabbed for too long can cause problems.
165 .B visualID\fP (class \fBVisualID\fP)
166 Specify which X visual to use by default. (Note carefully that this resource
167 is called \fBvisualID\fP, not merely \fBvisual\fP; if you set the \fBvisual\fP
168 resource instead, things will malfunction in obscure ways for obscure reasons.)
170 Legal values for the \fBVisualID\fP resource are:
174 Use the screen's default visual (the visual of the root window.)
178 Use the visual which supports the most colors. Note, however, that the
179 visual with the most colors might be a TrueColor visual, which does not
180 support colormap animation. Some programs have more interesting behavior
181 when run on PseudoColor visuals than on TrueColor.
184 Use a monochrome visual, if there is one.
187 Use a grayscale or staticgray visual, if there is one and it has more than
188 one plane (that is, it's not monochrome.)
191 Use the best of the color visuals, if there are any.
194 Use the visual that is best for OpenGL programs. (OpenGL programs have
195 somewhat different requirements than other X programs.)
198 where \fIclass\fP is one of \fBStaticGray\fP, \fBStaticColor\fP,
199 \fBTrueColor\fP, \fBGrayScale\fP, \fBPseudoColor\fP, or \fBDirectColor\fP.
200 Selects the deepest visual of the given class.
203 where \fInumber\fP (decimal or hex) is interpreted as a visual id number,
206 program; in this way you can have finer control over exactly which visual
207 gets used, for example, to select a shallower one than would otherwise
212 Note that this option specifies only the \fIdefault\fP visual that will
213 be used: the visual used may be overridden on a program-by-program basis.
214 See the description of the \fBprograms\fP resource, below.
217 .B installColormap\fP (class \fBBoolean\fP)
218 Install a private colormap while the screensaver is active, so that the
219 graphics hacks can get as many colors as possible. This is the
220 default. (This only applies when the screen's default visual is being
221 used, since non-default visuals get their own colormaps automatically.)
222 This can also be overridden on a per-hack basis: see the discussion of
223 the \fBdefault\-n\fP name in the section about the \fBprograms\fP resource.
225 .B verbose\fP (class \fBBoolean\fP)
226 Whether to print diagnostics. Default false.
228 .B timestamp\fP (class \fBBoolean\fP)
229 Whether to print the time of day along with any other diagnostic messages.
232 .B splash\fP (class \fBBoolean\fP)
233 Whether to display a splash screen at startup. Default true.
235 .B splashDuration\fP (class \fBTime\fP)
236 How long the splash screen should remain visible; default 5 seconds.
238 .B helpURL\fP (class \fBURL\fP)
239 The splash screen has a \fIHelp\fP button on it. When you press it, it will
240 display the web page indicated here in your web browser.
242 .B loadURL\fP (class \fBLoadURL\fP)
243 This is the shell command used to load a URL into your web browser.
244 The default setting will load it into Netscape if it is already running,
245 otherwise, will launch a new Netscape looking at the \fIhelpURL\fP.
247 .B demoCommand\fP (class \fBDemoCommand\fP)
248 This is the shell command run when the \fIDemo\fP button on the splash window
249 is pressed. It defaults to \fIxscreensaver\-demo\fP.
251 .B prefsCommand\fP (class \fBPrefsCommand\fP)
252 This is the shell command run when the \fIPrefs\fP button on the splash window
253 is pressed. It defaults to \fIxscreensaver\-demo\ \-prefs\fP.
255 .B nice\fP (class \fBNice\fP)
256 The sub-processes created by \fIxscreensaver\fP will be ``niced'' to this
257 level, so that they are given lower priority than other processes on the
258 system, and don't increase the load unnecessarily. The default is 10.
260 (Higher numbers mean lower priority; see
264 .B fade\fP (class \fBBoolean\fP)
265 If this is true, then when the screensaver activates, the current contents
266 of the screen will fade to black instead of simply winking out. This only
267 works on displays with writable colormaps, that is, if the screen's default
268 visual is a PseudoColor visual. A fade will also be done when
269 switching graphics hacks (when the \fIcycle\fP timer expires.)
272 .B unfade\fP (class \fBBoolean\fP)
273 If this is true, then when the screensaver deactivates, the original contents
274 of the screen will fade in from black instead of appearing immediately. This
275 only works on displays with writable colormaps, and if \fIfade\fP is true
276 as well. Default false.
278 .B fadeSeconds\fP (class \fBTime\fP)
279 If \fIfade\fP is true, this is how long the fade will be in
280 seconds (default 3 seconds.)
282 .B fadeTicks\fP (class \fBInteger\fP)
283 If \fIfade\fP is true, this is how many times a second the colormap will
284 be changed to effect a fade. Higher numbers yield smoother fades, but
285 may make the fades take longer than the specified \fIfadeSeconds\fP if
286 your server isn't fast enough to keep up. Default 20.
288 .B captureStderr\fP (class \fBBoolean\fP)
289 Whether \fIxscreensaver\fP should redirect its stdout and stderr streams to
290 the window itself. Since its nature is to take over the screen, you would not
291 normally see error messages generated by xscreensaver or the sub-programs it
292 runs; this resource will cause the output of all relevant programs to be
293 drawn on the screensaver window itself, as well as being written to the
294 controlling terminal of the screensaver driver process. Default true.
296 .B font\fP (class \fBFont\fP)
297 The font used for the stdout/stderr text, if \fBcaptureStderr\fP is true.
298 Default \fB*\-medium\-r\-*\-140\-*\-m\-*\fP (a 14 point fixed-width font.)
300 .B programs\fP (class \fBPrograms\fP)
301 The graphics hacks which \fIxscreensaver\fP runs when the user is idle.
302 The value of this resource is a string, one \fIsh\fP-syntax command per line.
303 Each line must contain exactly one command: no semicolons, no ampersands.
305 When the screensaver starts up, one of these is selected at random, and
306 run. After the \fIcycle\fP period expires, it is killed, and another
309 If the value of this resource is empty, then no programs will be run; the
310 screen will simply be made black.
312 If the display has multiple screens, then a different program will be run
313 for each screen. (All screens are blanked and unblanked simultaniously.)
315 Note that you must escape the newlines; here is an example of how you
316 might set this in your \fI~/.xscreensaver\fP file:
322 ico -r -faces -sleep 1 -obj ico \\n\\
323 xdaliclock -builtin2 -root \\n\\
324 xv -root -rmode 5 image.gif -quit \\n
328 Make sure your \fB$PATH\fP environment variable is set up correctly
329 \fIbefore\fP xscreensaver is launched, or it won't be able to find the
330 programs listed in the \fIprograms\fP resource.
332 To use a program as a screensaver, two things are required: that that
333 program draw on the root window (or be able to be configured to draw on
334 the root window); and that that program understand ``virtual root''
335 windows, as used by virtual window managers such as
337 (Generally, this is accomplished by just including the \fI"vroot.h"\fP
338 header file in the program's source.)
340 If there are some programs that you want to run only when using a color
341 display, and others that you want to run only when using a monochrome
342 display, you can specify that like this:
344 mono: mono-program -root \\n\\
345 color: color-program -root \\n\\
349 More generally, you can specify the kind of visual that should be used for
350 the window on which the program will be drawing. For example, if one
351 program works best if it has a colormap, but another works best if it has
352 a 24-bit visual, both can be accommodated:
354 PseudoColor: cmap-program -root \\n\\
355 TrueColor: 24bit-program -root \\n\\
359 In addition to the symbolic visual names described above (in the discussion
360 of the \fIvisualID\fP resource) one other visual name is supported in
361 the \fIprograms\fP list:
365 This is like \fBdefault\fP, but also requests the use of the default colormap,
366 instead of a private colormap. (That is, it behaves as if
367 the \fI\-no\-install\fP command-line option was specified, but only for
368 this particular hack.) This is provided because some third-party programs
369 that draw on the root window (notably:
373 make assumptions about the visual and colormap of the root window:
374 assumptions which xscreensaver can violate.
377 If you specify a particular visual for a program, and that visual does not
378 exist on the screen, then that program will not be chosen to run. This
379 means that on displays with multiple screens of different depths, you can
380 arrange for appropriate hacks to be run on each. For example, if one screen
381 is color and the other is monochrome, hacks that look good in mono can be
382 run on one, and hacks that only look good in color will show up on the other.
386 Normally you won't need to change the following resources:
389 .B pointerPollTime\fP (class \fBTime\fP)
390 When server extensions are not in use, this controls how
391 frequently \fIxscreensaver\fP checks to see if the mouse position or buttons
392 have changed. Default 5 seconds.
394 .B windowCreationTimeout\fP (class \fBTime\fP)
395 When server extensions are not in use, this controls the delay between when
396 windows are created and when \fIxscreensaver\fP selects events on them.
399 .B initialDelay\fP (class \fBTime\fP)
400 When server extensions are not in use, \fIxscreensaver\fP will wait this many
401 seconds before selecting events on existing windows, under the assumption that
402 \fIxscreensaver\fP is started during your login procedure, and the window
403 state may be in flux. Default 0. (This used to default to 30, but that was
404 back in the days when slow machines and X terminals were more common...)
406 .B sgiSaverExtension\fP (class \fBBoolean\fP)
407 There are a number of different X server extensions which can make
408 xscreensaver's job easier. The next few resources specify whether these
409 extensions should be utilized if they are available.
411 This resource controls whether the SGI \fBSCREEN_SAVER\fP server extension
412 will be used to decide whether the user is idle. This is the default
413 if \fIxscreensaver\fP has been compiled with support for this
414 extension (which is the default on SGI systems.). If it is available,
415 the \fBSCREEN_SAVER\fP method is faster and more reliable than what will
416 be done otherwise, so use it if you can. (This extension is only available
417 on Silicon Graphics systems, unfortunately.)
419 .B mitSaverExtension\fP (class \fBBoolean\fP)
420 This resource controls whether the \fBMIT\-SCREEN\-SAVER\fP server extension
421 will be used to decide whether the user is idle. However, the default for
422 this resource is \fIfalse\fP, because even if this extension is available,
423 it is flaky (and it also makes the \fBfade\fP option not work properly.)
424 Use of this extension is not recommended.
426 .B xidleExtension\fP (class \fBBoolean\fP)
427 This resource controls whether the \fBXIDLE\fP server extension will be
428 used to decide whether the user is idle. This is the default
429 if \fIxscreensaver\fP has been compiled with support for this extension.
430 (This extension is only available for X11R4 and X11R5 systems, unfortunately.)
432 .B procInterrupts\fP (class \fBBoolean\fP)
433 This resource controls whether the \fB/proc/interrupts\fP file should be
434 consulted to decide whether the user is idle. This is the default
435 if \fIxscreensaver\fP has been compiled on a system which supports this
436 mechanism (i.e., Linux systems.)
438 The benefit to doing this is that \fIxscreensaver\fP can note that the user
439 is active even when the X console is not the active one: if the user is
440 typing in another virtual console, xscreensaver will notice that and will
441 fail to activate. For example, if you're playing Quake in VGA-mode,
442 xscreensaver won't wake up in the middle of your game and start competing
445 The drawback to doing this is that perhaps you \fIreally do\fP want idleness
446 on the X console to cause the X display to lock, even if there is activity
447 on other virtual consoles. If you want that, then set this option to False.
448 (Or just lock the X console manually.)
450 The default value for this resource is True, on systems where it works.
452 .B overlayStderr\fP (class \fBBoolean\fP)
453 If \fBcaptureStderr\fP is True, and your server supports ``overlay'' visuals,
454 then the text will be written into one of the higher layers instead of into
455 the same layer as the running screenhack. Set this to False to disable
456 that (though you shouldn't need to.)
458 .B overlayTextForeground\fP (class \fBForeground\fP)
459 The foreground color used for the stdout/stderr text, if \fBcaptureStderr\fP
460 is true. Default: Yellow.
462 .B overlayTextBackground\fP (class \fBBackground\fP)
463 The background color used for the stdout/stderr text, if \fBcaptureStderr\fP
464 is true. Default: Black.
466 .B bourneShell\fP (class \fBBourneShell\fP)
467 The pathname of the shell that \fIxscreensaver\fP uses to start subprocesses.
468 This must be whatever your local variant of \fB/bin/sh\fP is: in particular,
469 it must not be \fBcsh\fP.
470 .SH COMMAND-LINE OPTIONS
472 also accepts the following command line options. Except for
473 the \fI\-display\fP option, these command-line options are all
474 simply shorthand for the X resources described in
475 the \fIConfiguration\fP section, above.
477 .B \-display \fIhost:display.screen\fP
478 The X display to use. For displays with multiple screens, XScreenSaver
479 will manage all screens on the display simultaniously; the \fIscreen\fP
480 argument (the ``default'' screen) says which screen should be used for
481 dialog boxes (the password window, \fIDemo Mode\fP, etc.)
483 .B \-timeout \fIminutes\fP
484 Same as the \fItimeout\fP resource.
486 .B \-cycle \fIminutes\fP
487 Same as the \fIcycle\fP resource.
490 Same as setting the \fIlock\fP resource to \fItrue\fP.
493 Same as setting the \fIlock\fP resource to \fIfalse\fP.
495 .B \-lock\-timeout \fIminutes\fP
496 Same as the \fIlockTimeout\fP resource.
498 .B \-visual \fIvisual\fP
499 Same as the \fIvisualID\fP resource.
502 Same as setting the \fIinstallColormap\fP resource to \fItrue\fP.
505 Same as setting the \fIinstallColormap\fP resource to \fIfalse\fP.
508 Same as setting the \fIverbose\fP resource to \fItrue\fP.
511 Same as setting the \fIverbose\fP resource to \fIfalse\fP.
514 Same as setting the \fItimestamp\fP resource to \fItrue\fP.
517 Same as setting the \fIcaptureStderr\fP resource to \fItrue\fP.
519 .B \-no\-capture\-stderr
520 Same as setting the \fIcaptureStderr\fP resource to \fIfalse\fP.
523 Same as setting the \fIsplash\fP resource to \fItrue\fP.
526 Same as setting the \fIsplash\fP resource to \fIfalse\fP.
528 .B \-nice \fIinteger\fP
529 Same as the \fInice\fP resource.
532 Same as setting the \fIsgiSaverExtension\fP resource to \fItrue\fP.
534 .B \-no\-sgi\-extension
535 Same as setting the \fIsgiSaverExtension\fP resource to \fIfalse\fP.
538 Same as setting the \fImitSaverExtension\fP resource to \fItrue\fP.
540 .B \-no\-mit\-extension
541 Same as setting the \fImitSaverExtension\fP resource to \fIfalse\fP.
543 .B \-xidle\-extension
544 Same as setting the \fIxidleExtension\fP resource to \fItrue\fP.
546 .B \-no\-xidle\-extension
547 Same as setting the \fIxidleExtension\fP resource to \fIfalse\fP.
549 .B \-proc\-interrupts
550 Same as setting the \fIprocInterrupts\fP resource to \fItrue\fP.
552 .B \-no\-proc\-interrupts
553 Same as setting the \fIprocInterrupts\fP resource to \fIfalse\fP.
555 .B \-xrm \fIresource-specification\fP
556 As with all other Xt programs, you can specify X resources on the command-line
557 using the \fI\-xrm\fP argument. Most of the interesting resources have
558 command-line equivalents, however.
560 When it is time to activate the screensaver, a full-screen black window is
561 created on each screen of the display. Each window is created in such a way
562 that, to any subsequently-created programs, it will appear to be a ``virtual
563 root'' window. Because of this, any program which draws on the root
564 window (and which understands virtual roots) can be used as a screensaver.
566 When the user becomes active again, the screensaver windows are unmapped, and
567 the running subprocesses are killed by sending them \fBSIGTERM\fP. This is
568 also how the subprocesses are killed when the screensaver decides that it's
569 time to run a different demo: the old one is killed and a new one is launched.
571 Before launching a subprocess, \fIxscreensaver\fP stores an appropriate value
572 for \fB$DISPLAY\fP in the environment that the child will recieve. (This is
573 so that if you start \fIxscreensaver\fP with a \fI-display\fP argument, the
574 programs which \fIxscreensaver\fP launches will draw on the same display;
575 and so that the child will end up drawing on the appropriate screen of a
576 multi-headed display.)
578 When the screensaver turns off, or is killed, care is taken to restore
579 the ``real'' virtual root window if there is one. Because of this, it is
580 important that you not kill the screensaver process with \fIkill -9\fP if
581 you are running a virtual-root window manager. If you kill it with \-9,
582 you may need to restart your window manager to repair the damage. This
583 isn't an issue if you aren't running a virtual-root window manager.
585 For all the gory details, see the commentary at the top of xscreensaver.c.
587 You can control a running screensaver process by using the
588 .BR xscreensaver\-command (1)
591 Modern X servers contain support to power down the monitor after an idle
592 period. If the monitor has powered down, then \fIxscreensaver\fP will
593 notice this, and will not waste CPU by drawing graphics demos on a black
594 screen. An attempt will also be made to explicitly power the monitor
595 back up as soon as user activity is detected.
597 If your X server supports power management, then
599 will accept a \fBdpms\fP option. So, if you wanted \fIxscreensaver\fP
600 to activate after 5 minutes, but you wanted your monitor to power down
601 after one hour (3600 seconds) you would do this:
605 See the man page for the
607 program for details. (Note that power management requires both software
608 support in the X server, and hardware support in the monitor itself.)
610 You can run \fIxscreensaver\fP from your
612 session, so that the screensaver will run even when nobody is logged
615 The trick to using xscreensaver with \fIxdm\fP is this: keep in mind the
616 two very different states in which xscreensaver will be running:
619 .B 1: Nobody logged in.
621 If you're thinking of running xscreensaver from XDM at all, then it's
622 probably because you want graphics demos to be running on the console
623 when nobody is logged in there. In this case, xscreensaver will function
624 only as a screen saver, not a screen locker: it doesn't make sense
625 for xscreensaver to lock the screen, since nobody is logged in yet!
626 The only thing on the screen is the XDM login prompt.
628 .B 2: Somebody logged in.
630 Once someone has logged in through the XDM login window, the situation is
631 very different. For example: now it makes sense to lock the screen (and
632 prompt for the logged in user's password); and now xscreensaver should
633 consult that user's \fI~/.xscreensaver\fP file; and so on.
636 The difference between these two states comes down to a question of,
637 which user is the \fIxscreensaver\fP process running as? For the first
638 state, it doesn't matter. If you start \fIxscreensaver\fP in the usual
639 XDM way, then xscreensaver will probably end up running as root, which
640 is fine for the first case (the ``nobody logged in'' case.)
642 However, once someone is logged in, running as root is no longer fine:
643 because xscreensaver will be consulting root's \fI.xscreensaver\fP file
644 instead of that of the logged in user, and won't be prompting for the
645 logged in user's password, and so on. (This is not a security problem,
646 it's just not what you want.)
648 So, once someone has logged in, you want xscreensaver to be running as that
649 user. The way to accomplish this is to kill the old xscreensaver process
650 and start a new one (as the new user.)
652 The simplest way to accomplish all of this is as follows:
655 .B 1: Launch xscreensaver before anyone logs in.
657 To the file \fI/usr/lib/X11/xdm/Xsetup\fP, add the lines
659 xscreensaver-command -exit
662 This will run xscreensaver as root, over the XDM login window.
663 Moving the mouse will cause the screen to un-blank, and allow the user
664 to type their password at XDM to log in.
666 .B 2: Restart xscreensaver when someone logs in.
668 Near the top of the file \fI/usr/lib/X11/xdm/Xsession\fP, add those same lines:
670 xscreensaver-command -exit
673 When someone logs in, this will kill off the existing (root) xscreensaver
674 process, and start a new one, running as the user who has just logged in.
675 If the user's .xscreensaver file requests locking, they'll get it. They
676 will also get their own choice of timeouts, and graphics demos, and so on.
678 Alternately, each user could just put those lines in their
679 personal \fI~/.xsession\fP files.
682 Make sure you have \fB$PATH\fP set up correctly in the \fIXsetup\fP
683 and \fIXsession\fP scripts, or \fIxdm\fP won't be able to
684 find \fIxscreensaver\fP, and/or \fIxscreensaver\fP won't be able to
685 find its graphics demos.
687 (If your system does not seem to be executing the \fIXsetup\fP file, you
688 may need to configure it to do so: the traditional way to do this is
689 to make that file the value of the \fIDisplayManager*setup\fP resource
690 in the \fI/usr/lib/X11/xdm/xdm-config\fP file. See the man page for
694 It is safe to run \fIxscreensaver\fP as root (as \fIxdm\fP is likely to do.)
695 If run as root, \fIxscreensaver\fP changes its effective user and group ids
696 to something safe (like \fI"nobody"\fP) before connecting to the X server
697 or launching user-specified programs.
699 An unfortunate side effect of this (important) security precaution is that
700 it may conflict with cookie-based authentication.
702 If you get "connection refused" errors when running \fIxscreensaver\fP
703 from \fIxdm\fP, then this probably means that you have
705 or some other security mechanism turned on. One way around this is to
706 add \fB"xhost\ +localhost"\fP to \fIXsetup\fP, just before \fIxscreensaver\fP
709 Note that this will give access to the X server to anyone capable of logging
710 in to the local machine, so in some environments, this might not be
711 appropriate. If turning off file-system-based access control is not
712 acceptable, then running \fIxscreensaver\fP from the \fIXsetup\fP file
713 might not be possible, and xscreensaver will only work when running as
714 a normal, unprivileged user.
716 For more information on the X server's access control mechanisms, see the
723 .SH USING CDE (COMMON DESKTOP ENVIRONMENT)
724 The easiest way to use \fIxscreensaver\fP on a system with CDE is to simply
725 switch off the built-in CDE screensaver, and use \fIxscreensaver\fP instead;
726 and second, to tell the front panel to run
727 .BR xscreensaver\-command (1)
728 with the \fI\-lock\fP option when the \fILock\fP icon is clicked.
730 To accomplish this involves five steps:
733 \fB1: Switch off CDE's locker\fP
734 Do this by turning off ``\fIScreen Saver and Screen Lock\fP'' in the
735 Screen section of the Style Manager.
737 \fB2: Edit sessionetc\fP
738 Edit the file \fI~/.dt/sessions/sessionetc\fP and add to it the line
742 This will cause \fIxscreensaver\fP to be launched when you log in.
743 (As always, make sure that xscreensaver and the graphics demos are on
744 your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
745 and/or \fI.dtprofile\fP, not \fI.login\fP.)
747 \fB3: Create XScreenSaver.dt\fP
748 Create a file called \fI~/.dt/types/XScreenSaver.dt\fP with the following
755 EXEC_STRING xscreensaver-command -lock
760 This defines a ``lock'' command for the CDE front panel, that knows how
761 to talk to \fIxscreensaver\fP.
763 \fB4: Create Lock.fp\fP
764 Create a file called \fI~/.dt/types/Lock.fp\fP with the following
770 CONTAINER_NAME Switch
771 CONTAINER_TYPE SWITCH
775 PUSH_ACTION XScreenSaver
776 HELP_TOPIC FPOnItemLock
780 This associates the CDE front panel ``Lock'' icon with the lock command
781 we just defined in step 3.
784 Select ``\fIRestart Workspace Manager\fP'' from the popup menu to make
785 your changes take effect. If things seem not to be working, check the
786 file \fI~/.dt/errorlog\fP for error messages.
788 .SH USING HP VUE (VISUAL USER ENVIRONMENT)
789 Since CDE is a descendant of VUE, the instructions for using xscreensaver
790 under VUE are similar to the above:
793 \fB1: Switch off VUE's locker\fP
794 Open the ``\fIStyle Manager\fP'' and select ``\fIScreen\fP.''
795 Turn off ``\fIScreen Saver and Screen Lock\fP'' option.
797 \fB2: Make sure you have a Session\fP
798 Next, go to the Style Manager's, ``\fIStartup\fP'' page.
799 Click on ``\fISet Home Session\fP'' to create a session, then
800 on ``\fIReturn to Home Session\fP'' to select this session each
803 \fB3: Edit vue.session\fP
804 Edit the file \fI~/.vue/sessions/home/vue.session\fP and add to it
807 vuesmcmd -screen 0 -cmd "xscreensaver"
809 This will cause \fIxscreensaver\fP to be launched when you log in.
810 (As always, make sure that xscreensaver and the graphics demos are on
811 your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
812 and/or \fI.profile\fP, not \fI.login\fP.)
814 \fB3: Edit vuewmrc\fP
815 Edit the file \fI~/.vue/vuewmrc\fP and add (or change) the Lock control:
821 PUSH_ACTION f.exec "xscreensaver-command -lock"
825 This associates the VUE front panel ``Lock'' icon with the xscreensaver
831 .BR xscreensaver-command (1)
832 program is a perfect candidate for something to add to your window manager's
833 popup menus. If you use
837 or (probably) any of \fItwm\fP's many descendants, you can do it like this:
840 \fB1. Create ~/.mwmrc (or ~/.twmrc or ...)\fP
841 If you don't have a \fI~/.mwmrc\fP file (or, on SGIs, a \fI~/.4Dwmrc\fP file;
842 or, with twm, a \fI~/.twmrc\fP file) then create one by making a copy of
843 the \fI/usr/lib/X11/system.mwmrc\fP
844 file (or \fI/usr/lib/X11/twm/system.twmrc\fP, and so on.)
846 \fB2. Add a menu definition.\fP
851 "Blank Screen Now" !"sleep 3; xscreensaver-command -activate"
852 "Lock Screen Now" !"sleep 3; xscreensaver-command -lock"
853 "Screen Saver Demo" !"xscreensaver-demo"
854 "Screen Saver Preferences" !"xscreensaver-demo -prefs"
855 "Reinitialize Screen Saver" !"xscreensaver-command -restart"
856 "Kill Screen Saver" !"xscreensaver-command -exit"
857 "Launch Screen Saver" !"xscreensaver &"
861 \fB3. Add the menu\fP
866 find the section of the file that says \fIMenu DefaultRootMenu\fP.
869 it will probably be \fImenu "defops"\fP. If you add a line somewhere
870 in that menu definition that reads
872 "XScreenSaver" f.menu XScreenSaver
874 then this will add an XScreenSaver sub-menu to your default root-window
875 popup menu. Alternately, you could just put the xscreensaver menu items
876 directly into the root menu.
879 Other window managers are guaranteed to do things gratuitously differently.
881 Bugs? There are no bugs. Ok, well, maybe. If you find one, please let
882 me know. http://www.jwz.org/xscreensaver/bugs.html explains how to
883 construct the most useful bug reports.
886 If xscreensaver has been launched from
888 before anyone has logged in, you will need to kill and then restart the
889 xscreensaver daemon after you have logged in, or you will be confused by
890 the results. (For example, locking won't work, and your \fI~/.xscreensaver\fP
891 file will be ignored.)
893 When you are logged in, you want the \fIxscreensaver\fP daemon to be
894 running under \fIyour\fP user id, not as root or some other user.
896 If it has already been started by \fIxdm\fP, you can kill it by sending
897 it the \fBexit\fP command, and then re-launching it as you, by putting
898 something like the following in your personal X startup script:
900 xscreensaver-command -exit
903 The ``\fIUsing XDM(1)\fP'' section, above, goes into more detail, and explains
904 how to configure the system to do this for all users automatically.
906 .B Locking and root logins
907 In order for it to be safe for xscreensaver to be launched by \fIxdm\fP,
908 certain precautions had to be taken, among them that xscreensaver never
909 runs as \fIroot\fP. In particular, if it is launched as root (as \fIxdm\fP
910 is likely to do), xscreensaver will disavow its privileges, and switch
911 itself to a safe user id (such as \fInobody\fP.)
913 An implication of this is that if you log in as \fIroot\fP on the console,
914 xscreensaver will refuse to lock the screen (because it can't tell
915 the difference between \fIroot\fP being logged in on the console, and a
916 normal user being logged in on the console but xscreensaver having been
922 The solution to this is simple: you shouldn't be logging in on the console
923 as \fIroot\fP in the first place! (What, are you crazy or something?)
925 Proper Unix hygiene dictates that you should log in as yourself, and
927 to \fIroot\fP as necessary. People who spend their day logged in
928 as \fIroot\fP are just begging for disaster.
931 For xscreensaver to work when launched by
933 programs running on the local machine as user \fI"nobody"\fP must be
934 able to connect to the X server. This means that if you want to run
935 xscreensaver on the console while nobody is logged in, you may need
936 to disable cookie-based access control (and allow all users who can log
937 in to the local machine to connect to the display.)
939 You should be sure that this is an acceptable thing to do in your
940 environment before doing it. See the ``\fIUsing XDM(1)\fP'' section,
941 above, for more details.
943 If anyone has suggestions on how xscreensaver could be made to work with
945 without first turning off \fI.Xauthority\fP-based access control, please
949 If you get an error message at startup like ``couldn't get password
950 of \fIuser\fP'' then this probably means that you're on a system in which
953 library routine can only be effectively used by root. If this is the case,
954 then \fIxscreensaver\fP must be installed as setuid to root in order for
955 locking to work. Care has been taken to make this a safe thing to do.
957 It also may mean that your system uses shadow passwords instead of the standard
959 interface; in that case, you may need to change some options
960 with \fIconfigure\fP and recompile.
962 If you change your password after xscreensaver has been launched, it will
963 continue using your old password to unlock the screen until xscreensaver
964 is restarted. So, after you change your password, you'll have to do
966 xscreensaver-command -restart
968 to make \fIxscreensaver\fP notice.
971 If your system uses PAM (Pluggable Authentication Modules), then in order
972 for xscreensaver to use PAM properly, PAM must be told about xscreensaver.
973 The xscreensaver installation process should update the PAM data (on Linux,
974 by creating the file \fI/etc/pam.d/xscreensaver\fP for you, and on Solaris,
975 by telling you what lines to add to the \fI/etc/pam.conf\fP file.)
977 If the PAM configuration files do not know about xscreensaver, then
978 you \fImight\fP be in a situation where xscreensaver will refuse to ever
981 This is a design flaw in PAM (there is no way for a client to tell the
982 difference between PAM responding ``I have never heard of your module,''
983 and responding, ``you typed the wrong password.'') As far as I can tell,
984 there is no way for xscreensaver to automatically work around this, or
985 detect the problem in advance, so if you have PAM, make sure it is
986 configured correctly!
988 .B Colormap lossage: TWM
989 The \fBinstallColormap\fP option doesn't work very well with the
991 window manager and its descendants.
993 There is a race condition between the screensaver and this window manager,
994 which can result in the screensaver's colormap not getting installed
995 properly, meaning the graphics hacks will appear in essentially random
996 colors. (If the screen goes white instead of black, this is probably why.)
1002 window managers don't have this problem. The race condition exists
1003 because X (really, ICCCM) does not provide a way for an OverrideRedirect
1004 window to have its own colormap, short of grabbing the server (which is
1005 neither a good idea, nor really possible with the current design.) What
1006 happens is that, as soon as xscreensaver installs its colormap, \fBtwm\fP
1007 responds to the resultant \fBColormapNotify\fP event by re-instaling the
1008 default colormap. Apparently, \fBtwm\fP doesn't \fIalways\fP do this; it
1009 seems to do it regularly if the screensaver is activated from a menu item,
1010 but seems to not do it if the screensaver comes on of its own volition, or
1011 is activated from another console.
1014 .B Attention, window manager authors!
1015 You should only call
1016 .BR XInstallColormap (3)
1017 in response to user events. That is, it is appropriate to install a colormap
1018 in response to \fBFocusIn\fP, \fBFocusOut\fP, \fBEnterNotify\fP,
1019 and \fBLeaveNotify\fP events; but it is not appropriate to call it in
1020 response to \fBColormapNotify\fP events. If you install colormaps in
1021 response to \fIapplication\fP actions as well as in response to \fIuser\fP
1022 actions, then you create the situation where it is impossible for
1023 override-redirect applications (such as xscreensaver) to display their
1024 windows in the proper colors.
1027 .B Colormap lossage: XV, XAnim, XEarth
1028 Some programs don't operate properly on visuals other than the default one,
1029 or with colormaps other than the default one. See the discussion of the
1030 magic "default-n" visual name in the description of the \fBprograms\fP
1031 resource in the \fIConfiguration\fP section. When programs only work with
1032 the default colormap, you need to use a syntax like this:
1034 default-n: xv -root image-1.gif -quit \\n\\
1035 default-n: xearth -nostars -wait 0 \\n\\
1037 It would also work to turn off the \fBinstallColormap\fP option altogether,
1038 but that would deny extra colors to those programs that \fIcan\fP take
1042 Although this program ``nices'' the subprocesses that it starts,
1043 graphics-intensive subprograms can still overload the machine by causing
1044 the X server process itself (which is not ``niced'') to suck a lot of
1045 cycles. Care should be taken to slow down programs intended for use as
1046 screensavers by inserting strategic calls to
1050 (or making liberal use of any \fI\-delay\fP options which the programs
1053 Note that the OpenGL-based graphics demos are real pigs on machines that
1054 don't have texture hardware.
1056 Also, an active screensaver will cause your X server to be pretty much
1057 permanently swapped in; but the same is true of any program that draws
1063 .B Latency and Responsiveness
1064 If the subprocess is drawing too quickly and the connection to the X
1065 server is a slow one (such as an X terminal running over a phone line) then
1066 the screensaver might not turn off right away when the user becomes active
1069 demo has this problem if being run in full-speed mode). This can be
1070 alleviated by inserting strategic calls to
1072 in code intended for use as a screensaver. This prevents too much graphics
1073 activity from being buffered up.
1075 .B XFree86's Magic Keystrokes
1076 The XFree86 X server traps certain magic keystrokes before client programs ever
1077 see them. Two that are of note are Ctrl+Alt+Backspace, which causes
1078 the X server to exit; and Ctrl+Alt+F\fIn\fP, which switches virtual consoles.
1079 The X server will respond to these keystrokes even if xscreensaver has the
1080 screen locked. Depending on your setup, you might consider this a problem.
1082 Unfortunately, there is no way for xscreensaver itself to override the
1083 interpretation of these keys. If you want to disable Ctrl+Alt+Backspace
1084 globally, you need to set the \fIDontZap\fP flag in
1085 your \fI/etc/X11/XF86Config\fP file. See the
1089 There is no way (as far as I can tell) to disable the VT-switching keystrokes.
1091 Some Linux systems come with a VT_LOCKSWITCH ioctl, that one could
1092 theoretically use to prevent VT-switching while the screen is locked;
1093 but unfortunately, this ioctl can only be used by root, which means
1094 that xscreensaver can't use it (since xscreensaver disavows its privileges
1095 shortly after startup, for security reasons.)
1097 Any suggestions for other solutions to this problem are welcome.
1100 Apparently there are some problems with XView programs getting confused
1101 and thinking that the screensaver window is the real root window even when
1102 the screensaver is not active: ClientMessages intended for the window manager
1103 are sent to the screensaver window instead. This could be solved by making
1104 xscreensaver forward all unrecognised ClientMessages to the real root window,
1105 but there may be other problems as well. If anyone has any insight on the
1106 cause of this problem, please let me know. (XView is an X11 toolkit that
1107 implements the (quite abominable) Sun OpenLook look-and-feel.)
1109 .B MIT Extension and Fading
1110 The \fBMIT-SCREEN-SAVER\fP extension is junk. Don't use it.
1112 When using the \fBMIT-SCREEN-SAVER\fP extension in conjunction with
1113 the \fBfade\fP option, you'll notice an unattractive flicker just before
1114 the fade begins. This is because the server maps a black window just before
1115 it tells the \fIxscreensaver\fP process to activate. The \fIxscreensaver\fP
1116 process immediately unmaps that window, but this results in a flicker. I
1117 haven't figured a way to get around this; it seems to be a fundamental
1118 property of the (mis-) design of this server extension.
1120 It sure would be nice if someone would implement the \fBSGI SCREEN_SAVER\fP
1121 extension in XFree86; it's dead simple, and works far better than the
1122 overengineered and broken \fBMIT-SCREEN-SAVER\fP extension.
1125 If you're running Irix 6.3, you might find that your monitor is powering down
1126 after an hour or two even if you've told it not to. This is fixed by SGI
1127 patches 2447 and 2537.
1129 If you're running Irix 6.5, this bug is back. I don't know a fix.
1131 .B MesaGL and Voodoo Cards
1132 If you have a 3Dfx/Voodoo card, the default settings for xscreensaver will
1133 run the GL-based graphics demos in such a way that they will not take
1134 advantage of the 3D acceleration hardware. The solution is to change
1135 the \fBprograms\fP entries for the GL hacks from this:
1141 MESA_GLX_FX=fullscreen gears \\n\\
1143 That is, make sure that \fB$MESA_GLX_FX\fP is set to \fIfullscreen\fP, and
1144 don't tell the program to draw on the root window. This may seem strange,
1145 but the setup used by Mesa and these kinds of cards \fIis\fP strange!
1147 For those who don't know, these cards work by sitting between your normal
1148 video card and the monitor, and seizing control of the monitor when it's
1149 time to do 3D. But this means that accelerated 3D only happens in full-screen
1150 mode (you can't do it in a window, and you can't see the output of 3D and 2D
1151 programs simultaniously), and that 3D will probably drive your monitor at a
1152 lower resolution, as well. It's bizarre.
1154 If you find that GL programs only work properly when run as root, and not
1155 as normal users, then the problem is that your \fI/dev/3dfx\fP file is not
1156 configured properly. Check the Linux 3Dfx FAQ.
1159 If \fIprocInterrupts\fP is on (which is the default on Linux systems) and
1160 you're using some program that toggles the state of your keyboard LEDs,
1161 xscreensaver won't work right: turning those LEDs on or off causes a
1162 keyboard interrupt, which xscreensaver will interpret as user activity.
1163 So if you're using such a program, set the \fIprocInterrupts\fP resource
1167 If you are not making use of one of the server extensions (\fBXIDLE\fP,
1168 \fBSGI SCREEN_SAVER\fP, or \fBMIT-SCREEN-SAVER\fP), then it is possible, in
1169 rare situations, for \fIxscreensaver\fP to interfere with event propagation
1170 and make another X program malfunction. For this to occur, that other
1171 application would need to \fInot\fP select \fBKeyPress\fP events on its
1172 non-leaf windows within the first 30 seconds of their existence, but then
1173 select for them later. In this case, that client \fImight\fP fail to receive
1174 those events. This isn't very likely, since programs generally select a
1175 constant set of events immediately after creating their windows and then
1176 don't change them, but this is the reason that it's a good idea to install
1177 and use one of the server extensions instead, to work around this shortcoming
1180 In all these years, I've not heard of even a single case of this happening,
1181 but it is theoretically possible, so I'm mentioning it for completeness...
1184 There need to be a lot more graphics hacks. In particular, there should be
1185 a simulation of a Lavalite (tm).
1190 to get the default host and display number, and to inform the sub-programs
1191 of the screen on which to draw.
1194 to find the sub-programs to run.
1197 for the directory in which to read and write the \fI.xscreensaver\fP file.
1200 to get the name of a resource file that overrides the global resources
1201 stored in the RESOURCE_MANAGER property.
1203 The latest version can always be found at
1204 http://www.jwz.org/xscreensaver/
1207 .BR xscreensaver\-demo (1),
1208 .BR xscreensaver\-command (1),
1229 .BR decayscreen (1),
1254 .BR interference (1),
1257 .BR kaleidescope (1),
1289 .BR slidescreen (1),
1300 .BR superquadrics (1),
1316 .BR xbouncebits (1),
1327 Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999
1328 by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell
1329 this software and its documentation for any purpose is hereby granted without
1330 fee, provided that the above copyright notice appear in all copies and that
1331 both that copyright notice and this permission notice appear in supporting
1332 documentation. No representations are made about the suitability of this
1333 software for any purpose. It is provided "as is" without express or implied
1336 Jamie Zawinski <jwz@jwz.org>. Written in late 1991; first posted
1337 to comp.sources.x on 13-Aug-1992.
1339 Please let me know if you find any bugs or make any improvements.
1340 .SH ACKNOWLEDGEMENTS
1341 Thanks to the many people who have contributed graphics demos to the package.
1343 Thanks to David Wojtowicz for implementing \fIlockTimeout\fP.
1345 Thanks to Martin Kraemer for adding support for shadow passwords and
1346 locking-disabled diagnostics.
1348 Thanks to Patrick Moreau for the VMS port.
1350 Thanks to Mark Bowyer for figuring out how to hook it up to CDE.
1352 Thanks to Nat Lanza for the Kerberos support.
1354 Thanks to Bill Nottingham for the initial PAM support.
1356 And thanks to Jon A. Christopher for implementing the Athena dialog
1357 support, back in the days before Lesstif or Gtk were viable alternatives
projects / xscreensaver / blob