14 .TH XScreenSaver 1 "29-Mar-2001 (3.31)" "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 The easiest way to configure \fIxscreensaver\fP is to simply run the
83 .BR xscreensaver-demo (1)
84 program, and change the settings through the GUI. The rest of this
85 manual page describes lower level ways of changing settings.
87 Options to \fIxscreensaver\fP are stored in one of two places: in
88 a \fI.xscreensaver\fP file in your home directory; or in the X resource
89 database. If the \fI.xscreensaver\fP file exists, it overrides any settings
90 in the resource database.
92 The syntax of the \fI.xscreensaver\fP file is similar to that of
93 the \fI.Xdefaults\fP file; for example, to set the \fItimeout\fP paramter
94 in the \fI.xscreensaver\fP file, you would write the following:
98 whereas, in the \fI.Xdefaults\fP file, you would write
100 xscreensaver.timeout: 5
102 If you change a setting in the \fI.xscreensaver\fP file while xscreensaver
103 is already running, it will notice this, and reload the file. (The file will
104 be reloaded the next time the screen saver needs to take some action, such as
105 blanking or unblanking the screen, or picking a new graphics mode.)
107 If you change a setting in your X resource database, or if you want
108 xscreensaver to notice your changes immediately instead of the next time
109 it wakes up, then you will need to tell the running xscreensaver process
110 to re-initialize itself, like so:
112 xscreensaver-command -restart
114 Note that if you changed the \fI.Xdefaults\fP file, you might also need to run
119 If you want to set the system-wide defaults, then make your edits to
120 the xscreensaver app-defaults file, which should have been installed
121 when xscreensaver itself was installed. The app-defaults file will
122 usually be named /usr/lib/X11/app-defaults/XScreenSaver, but different
123 systems might keep it in a different place (for example,
124 /usr/openwin/lib/app-defaults/XScreenSaver on Solaris.)
126 When settings are changed in the Preferences dialog box (see above)
127 the current settings will be written to the \fI.xscreensaver\fP file.
128 (The \fI.Xdefaults\fP file and the app-defaults file will never be
129 written by xscreensaver itself.)
132 .B timeout\fP (class \fBTime\fP)
133 The screensaver will activate (blank the screen) after the keyboard and
134 mouse have been idle for this many minutes. Default 10 minutes.
136 .B cycle\fP (class \fBTime\fP)
137 After the screensaver has been running for this many minutes, the currently
138 running graphics-hack sub-process will be killed (with \fBSIGTERM\fP), and a
139 new one started. If this is 0, then the graphics hack will never be changed:
140 only one demo will run until the screensaver is deactivated by user activity.
143 .B lock\fP (class \fBBoolean\fP)
144 Enable locking: before the screensaver will turn off, it will require you
145 to type the password of the logged-in user (really, the person who ran
146 xscreensaver), or the root password. (\fBNote:\fP this doesn't work if the
147 screensaver is launched by
149 because it can't know the user-id of the logged-in user. See
150 the ``\fIUsing XDM(1)\fP'' section, below.
152 .B lockTimeout\fP (class \fBTime\fP)
153 If locking is enabled, this controls the length of the ``grace period''
154 between when the screensaver activates, and when the screen becomes locked.
155 For example, if this is 5, and \fI\-timeout\fP is 10, then after 10 minutes,
156 the screen would blank. If there was user activity at 12 minutes, no password
157 would be required to un-blank the screen. But, if there was user activity
158 at 15 minutes or later (that is, \fI\-lock\-timeout\fP minutes after
159 activation) then a password would be required. The default is 0, meaning
160 that if locking is enabled, then a password will be required as soon as the
163 .B passwdTimeout\fP (class \fBTime\fP)
164 If the screen is locked, then this is how many seconds the password dialog box
165 should be left on the screen before giving up (default 30 seconds.) This
166 should not be too large: the X server is grabbed for the duration that the
167 password dialog box is up (for security purposes) and leaving the server
168 grabbed for too long can cause problems.
170 .B dpmsEnabled\fP (class \fBBoolean\fP)
171 Whether power management is enabled.
173 .B dpmsStandby\fP (class \fBTime\fP)
174 If power management is enabled, how long until the monitor goes solid black.
176 .B dpmsSuspend\fP (class \fBTime\fP)
177 If power management is enabled, how long until the monitor goes into
180 .B dpmsOff\fP (class \fBTime\fP)
181 If power management is enabled, how long until the monitor powers down
182 completely. Note that these settings will have no effect unless both
183 the X server and the display hardware support power management; not
184 all do. See the \fIPower Management\fP section, below, for more
187 .B visualID\fP (class \fBVisualID\fP)
188 Specify which X visual to use by default. (Note carefully that this resource
189 is called \fBvisualID\fP, not merely \fBvisual\fP; if you set the \fBvisual\fP
190 resource instead, things will malfunction in obscure ways for obscure reasons.)
192 Legal values for the \fBVisualID\fP resource are:
196 Use the screen's default visual (the visual of the root window.)
200 Use the visual which supports the most colors. Note, however, that the
201 visual with the most colors might be a TrueColor visual, which does not
202 support colormap animation. Some programs have more interesting behavior
203 when run on PseudoColor visuals than on TrueColor.
206 Use a monochrome visual, if there is one.
209 Use a grayscale or staticgray visual, if there is one and it has more than
210 one plane (that is, it's not monochrome.)
213 Use the best of the color visuals, if there are any.
216 Use the visual that is best for OpenGL programs. (OpenGL programs have
217 somewhat different requirements than other X programs.)
220 where \fIclass\fP is one of \fBStaticGray\fP, \fBStaticColor\fP,
221 \fBTrueColor\fP, \fBGrayScale\fP, \fBPseudoColor\fP, or \fBDirectColor\fP.
222 Selects the deepest visual of the given class.
225 where \fInumber\fP (decimal or hex) is interpreted as a visual id number,
228 program; in this way you can have finer control over exactly which visual
229 gets used, for example, to select a shallower one than would otherwise
234 Note that this option specifies only the \fIdefault\fP visual that will
235 be used: the visual used may be overridden on a program-by-program basis.
236 See the description of the \fBprograms\fP resource, below.
239 .B installColormap\fP (class \fBBoolean\fP)
240 Install a private colormap while the screensaver is active, so that the
241 graphics hacks can get as many colors as possible. This is the
242 default. (This only applies when the screen's default visual is being
243 used, since non-default visuals get their own colormaps automatically.)
244 This can also be overridden on a per-hack basis: see the discussion of
245 the \fBdefault\-n\fP name in the section about the \fBprograms\fP resource.
247 .B verbose\fP (class \fBBoolean\fP)
248 Whether to print diagnostics. Default false.
250 .B timestamp\fP (class \fBBoolean\fP)
251 Whether to print the time of day along with any other diagnostic messages.
254 .B splash\fP (class \fBBoolean\fP)
255 Whether to display a splash screen at startup. Default true.
257 .B splashDuration\fP (class \fBTime\fP)
258 How long the splash screen should remain visible; default 5 seconds.
260 .B helpURL\fP (class \fBURL\fP)
261 The splash screen has a \fIHelp\fP button on it. When you press it, it will
262 display the web page indicated here in your web browser.
264 .B loadURL\fP (class \fBLoadURL\fP)
265 This is the shell command used to load a URL into your web browser.
266 The default setting will load it into Netscape if it is already running,
267 otherwise, will launch a new Netscape looking at the \fIhelpURL\fP.
269 .B demoCommand\fP (class \fBDemoCommand\fP)
270 This is the shell command run when the \fIDemo\fP button on the splash window
271 is pressed. It defaults to \fIxscreensaver\-demo\fP.
273 .B prefsCommand\fP (class \fBPrefsCommand\fP)
274 This is the shell command run when the \fIPrefs\fP button on the splash window
275 is pressed. It defaults to \fIxscreensaver\-demo\ \-prefs\fP.
277 .B nice\fP (class \fBNice\fP)
278 The sub-processes created by \fIxscreensaver\fP will be ``niced'' to this
279 level, so that they are given lower priority than other processes on the
280 system, and don't increase the load unnecessarily. The default is 10.
282 (Higher numbers mean lower priority; see
286 .B fade\fP (class \fBBoolean\fP)
287 If this is true, then when the screensaver activates, the current contents
288 of the screen will fade to black instead of simply winking out. This only
289 works on displays with writable colormaps, that is, if the screen's default
290 visual is a PseudoColor visual. A fade will also be done when
291 switching graphics hacks (when the \fIcycle\fP timer expires.)
294 .B unfade\fP (class \fBBoolean\fP)
295 If this is true, then when the screensaver deactivates, the original contents
296 of the screen will fade in from black instead of appearing immediately. This
297 only works on displays with writable colormaps, and if \fIfade\fP is true
298 as well. Default false.
300 .B fadeSeconds\fP (class \fBTime\fP)
301 If \fIfade\fP is true, this is how long the fade will be in
302 seconds (default 3 seconds.)
304 .B fadeTicks\fP (class \fBInteger\fP)
305 If \fIfade\fP is true, this is how many times a second the colormap will
306 be changed to effect a fade. Higher numbers yield smoother fades, but
307 may make the fades take longer than the specified \fIfadeSeconds\fP if
308 your server isn't fast enough to keep up. Default 20.
310 .B captureStderr\fP (class \fBBoolean\fP)
311 Whether \fIxscreensaver\fP should redirect its stdout and stderr streams to
312 the window itself. Since its nature is to take over the screen, you would not
313 normally see error messages generated by xscreensaver or the sub-programs it
314 runs; this resource will cause the output of all relevant programs to be
315 drawn on the screensaver window itself, as well as being written to the
316 controlling terminal of the screensaver driver process. Default true.
318 .B font\fP (class \fBFont\fP)
319 The font used for the stdout/stderr text, if \fBcaptureStderr\fP is true.
320 Default \fB*\-medium\-r\-*\-140\-*\-m\-*\fP (a 14 point fixed-width font.)
322 .B programs\fP (class \fBPrograms\fP)
323 The graphics hacks which \fIxscreensaver\fP runs when the user is idle.
324 The value of this resource is a string, one \fIsh\fP-syntax command per line.
325 Each line must contain exactly one command: no semicolons, no ampersands.
327 When the screensaver starts up, one of these is selected at random, and
328 run. After the \fIcycle\fP period expires, it is killed, and another
331 If the value of this resource is empty, then no programs will be run; the
332 screen will simply be made black.
334 If the display has multiple screens, then a different program will be run
335 for each screen. (All screens are blanked and unblanked simultaniously.)
337 Note that you must escape the newlines; here is an example of how you
338 might set this in your \fI~/.xscreensaver\fP file:
344 ico -r -faces -sleep 1 -obj ico \\n\\
345 xdaliclock -builtin2 -root \\n\\
346 xv -root -rmode 5 image.gif -quit \\n
350 Make sure your \fB$PATH\fP environment variable is set up correctly
351 \fIbefore\fP xscreensaver is launched, or it won't be able to find the
352 programs listed in the \fIprograms\fP resource.
354 To use a program as a screensaver, two things are required: that that
355 program draw on the root window (or be able to be configured to draw on
356 the root window); and that that program understand ``virtual root''
357 windows, as used by virtual window managers such as
359 (Generally, this is accomplished by just including the \fI"vroot.h"\fP
360 header file in the program's source.)
362 If there are some programs that you want to run only when using a color
363 display, and others that you want to run only when using a monochrome
364 display, you can specify that like this:
366 mono: mono-program -root \\n\\
367 color: color-program -root \\n\\
371 More generally, you can specify the kind of visual that should be used for
372 the window on which the program will be drawing. For example, if one
373 program works best if it has a colormap, but another works best if it has
374 a 24-bit visual, both can be accommodated:
376 PseudoColor: cmap-program -root \\n\\
377 TrueColor: 24bit-program -root \\n\\
381 In addition to the symbolic visual names described above (in the discussion
382 of the \fIvisualID\fP resource) one other visual name is supported in
383 the \fIprograms\fP list:
387 This is like \fBdefault\fP, but also requests the use of the default colormap,
388 instead of a private colormap. (That is, it behaves as if
389 the \fI\-no\-install\fP command-line option was specified, but only for
390 this particular hack.) This is provided because some third-party programs
391 that draw on the root window (notably:
395 make assumptions about the visual and colormap of the root window:
396 assumptions which xscreensaver can violate.
399 If you specify a particular visual for a program, and that visual does not
400 exist on the screen, then that program will not be chosen to run. This
401 means that on displays with multiple screens of different depths, you can
402 arrange for appropriate hacks to be run on each. For example, if one screen
403 is color and the other is monochrome, hacks that look good in mono can be
404 run on one, and hacks that only look good in color will show up on the other.
408 Normally you won't need to change the following resources:
411 .B pointerPollTime\fP (class \fBTime\fP)
412 When server extensions are not in use, this controls how
413 frequently \fIxscreensaver\fP checks to see if the mouse position or buttons
414 have changed. Default 5 seconds.
416 .B windowCreationTimeout\fP (class \fBTime\fP)
417 When server extensions are not in use, this controls the delay between when
418 windows are created and when \fIxscreensaver\fP selects events on them.
421 .B initialDelay\fP (class \fBTime\fP)
422 When server extensions are not in use, \fIxscreensaver\fP will wait this many
423 seconds before selecting events on existing windows, under the assumption that
424 \fIxscreensaver\fP is started during your login procedure, and the window
425 state may be in flux. Default 0. (This used to default to 30, but that was
426 back in the days when slow machines and X terminals were more common...)
428 .B sgiSaverExtension\fP (class \fBBoolean\fP)
429 There are a number of different X server extensions which can make
430 xscreensaver's job easier. The next few resources specify whether these
431 extensions should be utilized if they are available.
433 This resource controls whether the SGI \fBSCREEN_SAVER\fP server extension
434 will be used to decide whether the user is idle. This is the default
435 if \fIxscreensaver\fP has been compiled with support for this
436 extension (which is the default on SGI systems.). If it is available,
437 the \fBSCREEN_SAVER\fP method is faster and more reliable than what will
438 be done otherwise, so use it if you can. (This extension is only available
439 on Silicon Graphics systems, unfortunately.)
441 .B mitSaverExtension\fP (class \fBBoolean\fP)
442 This resource controls whether the \fBMIT\-SCREEN\-SAVER\fP server extension
443 will be used to decide whether the user is idle. However, the default for
444 this resource is \fIfalse\fP, because even if this extension is available,
445 it is flaky (and it also makes the \fBfade\fP option not work properly.)
446 Use of this extension is not recommended.
448 .B xidleExtension\fP (class \fBBoolean\fP)
449 This resource controls whether the \fBXIDLE\fP server extension will be
450 used to decide whether the user is idle. This is the default
451 if \fIxscreensaver\fP has been compiled with support for this extension.
452 (This extension is only available for X11R4 and X11R5 systems, unfortunately.)
454 .B procInterrupts\fP (class \fBBoolean\fP)
455 This resource controls whether the \fB/proc/interrupts\fP file should be
456 consulted to decide whether the user is idle. This is the default
457 if \fIxscreensaver\fP has been compiled on a system which supports this
458 mechanism (i.e., Linux systems.)
460 The benefit to doing this is that \fIxscreensaver\fP can note that the user
461 is active even when the X console is not the active one: if the user is
462 typing in another virtual console, xscreensaver will notice that and will
463 fail to activate. For example, if you're playing Quake in VGA-mode,
464 xscreensaver won't wake up in the middle of your game and start competing
467 The drawback to doing this is that perhaps you \fIreally do\fP want idleness
468 on the X console to cause the X display to lock, even if there is activity
469 on other virtual consoles. If you want that, then set this option to False.
470 (Or just lock the X console manually.)
472 The default value for this resource is True, on systems where it works.
474 .B overlayStderr\fP (class \fBBoolean\fP)
475 If \fBcaptureStderr\fP is True, and your server supports ``overlay'' visuals,
476 then the text will be written into one of the higher layers instead of into
477 the same layer as the running screenhack. Set this to False to disable
478 that (though you shouldn't need to.)
480 .B overlayTextForeground\fP (class \fBForeground\fP)
481 The foreground color used for the stdout/stderr text, if \fBcaptureStderr\fP
482 is true. Default: Yellow.
484 .B overlayTextBackground\fP (class \fBBackground\fP)
485 The background color used for the stdout/stderr text, if \fBcaptureStderr\fP
486 is true. Default: Black.
488 .B bourneShell\fP (class \fBBourneShell\fP)
489 The pathname of the shell that \fIxscreensaver\fP uses to start subprocesses.
490 This must be whatever your local variant of \fB/bin/sh\fP is: in particular,
491 it must not be \fBcsh\fP.
492 .SH COMMAND-LINE OPTIONS
494 also accepts the following command line options. Except for
495 the \fI\-display\fP option, these command-line options are all
496 simply shorthand for the X resources described in
497 the \fIConfiguration\fP section, above.
499 .B \-display \fIhost:display.screen\fP
500 The X display to use. For displays with multiple screens, XScreenSaver
501 will manage all screens on the display simultaniously; the \fIscreen\fP
502 argument (the ``default'' screen) says which screen should be used for
503 dialog boxes (the password window, \fIDemo Mode\fP, etc.)
505 .B \-timeout \fIminutes\fP
506 Same as the \fItimeout\fP resource.
508 .B \-cycle \fIminutes\fP
509 Same as the \fIcycle\fP resource.
512 Same as setting the \fIlock\fP resource to \fItrue\fP.
515 Same as setting the \fIlock\fP resource to \fIfalse\fP.
517 .B \-lock\-timeout \fIminutes\fP
518 Same as the \fIlockTimeout\fP resource.
520 .B \-visual \fIvisual\fP
521 Same as the \fIvisualID\fP resource.
524 Same as setting the \fIinstallColormap\fP resource to \fItrue\fP.
527 Same as setting the \fIinstallColormap\fP resource to \fIfalse\fP.
530 Same as setting the \fIverbose\fP resource to \fItrue\fP.
533 Same as setting the \fIverbose\fP resource to \fIfalse\fP.
536 Same as setting the \fItimestamp\fP resource to \fItrue\fP.
539 Same as setting the \fIcaptureStderr\fP resource to \fItrue\fP.
541 .B \-no\-capture\-stderr
542 Same as setting the \fIcaptureStderr\fP resource to \fIfalse\fP.
545 Same as setting the \fIsplash\fP resource to \fItrue\fP.
548 Same as setting the \fIsplash\fP resource to \fIfalse\fP.
550 .B \-nice \fIinteger\fP
551 Same as the \fInice\fP resource.
554 Same as setting the \fIsgiSaverExtension\fP resource to \fItrue\fP.
556 .B \-no\-sgi\-extension
557 Same as setting the \fIsgiSaverExtension\fP resource to \fIfalse\fP.
560 Same as setting the \fImitSaverExtension\fP resource to \fItrue\fP.
562 .B \-no\-mit\-extension
563 Same as setting the \fImitSaverExtension\fP resource to \fIfalse\fP.
565 .B \-xidle\-extension
566 Same as setting the \fIxidleExtension\fP resource to \fItrue\fP.
568 .B \-no\-xidle\-extension
569 Same as setting the \fIxidleExtension\fP resource to \fIfalse\fP.
571 .B \-proc\-interrupts
572 Same as setting the \fIprocInterrupts\fP resource to \fItrue\fP.
574 .B \-no\-proc\-interrupts
575 Same as setting the \fIprocInterrupts\fP resource to \fIfalse\fP.
577 .B \-xrm \fIresource-specification\fP
578 As with all other Xt programs, you can specify X resources on the command-line
579 using the \fI\-xrm\fP argument. Most of the interesting resources have
580 command-line equivalents, however.
582 When it is time to activate the screensaver, a full-screen black window is
583 created on each screen of the display. Each window is created in such a way
584 that, to any subsequently-created programs, it will appear to be a ``virtual
585 root'' window. Because of this, any program which draws on the root
586 window (and which understands virtual roots) can be used as a screensaver.
588 When the user becomes active again, the screensaver windows are unmapped, and
589 the running subprocesses are killed by sending them \fBSIGTERM\fP. This is
590 also how the subprocesses are killed when the screensaver decides that it's
591 time to run a different demo: the old one is killed and a new one is launched.
593 Before launching a subprocess, \fIxscreensaver\fP stores an appropriate value
594 for \fB$DISPLAY\fP in the environment that the child will receive. (This is
595 so that if you start \fIxscreensaver\fP with a \fI-display\fP argument, the
596 programs which \fIxscreensaver\fP launches will draw on the same display;
597 and so that the child will end up drawing on the appropriate screen of a
598 multi-headed display.)
600 When the screensaver turns off, or is killed, care is taken to restore
601 the ``real'' virtual root window if there is one. Because of this, it is
602 important that you not kill the screensaver process with \fIkill -9\fP if
603 you are running a virtual-root window manager. If you kill it with \-9,
604 you may need to restart your window manager to repair the damage. This
605 isn't an issue if you aren't running a virtual-root window manager.
607 For all the gory details, see the commentary at the top of xscreensaver.c.
609 You can control a running screensaver process by using the
610 .BR xscreensaver\-command (1)
613 Modern X servers contain support to power down the monitor after an idle
614 period. If the monitor has powered down, then \fIxscreensaver\fP will
615 notice this (after a few minutes), and will not waste CPU by drawing
616 graphics demos on a black screen. An attempt will also be made to
617 explicitly power the monitor back up as soon as user activity is detected.
619 As of version 3.28, the \fI~/.xscreensaver\fP file controls the
620 configuration of your display's power management settings: if you have
623 to change your power management settings, then xscreensaver will
624 override those changes with the values specified
625 in \fI~/.xscreensaver\fP (or with its built-in defaults, if there
626 is no \fI~/.xscreensaver\fP file yet.)
628 To change your power management settings, run
629 .BR xscreensaver\-demo (1)
630 and change the various timeouts through the user interface.
631 Alternately, you can edit the \fI~/.xscreensaver\fP file directly.
633 If the power management section is grayed out in the
634 .BR xscreensaver\-demo (1)
635 window, then that means that your X server does not support
636 the XDPMS extension, and so control over the monitor's power state
639 If you're using a laptop, don't be surprised if changing the DPMS
640 settings has no effect: many laptops have monitor power-saving behavior
641 built in at a very low level that is invisible to Unix and X. On such
642 systems, you can typically only adjust the power-saving delays by
643 changing settings in the BIOS in some hardware-specific way.
645 You can run \fIxscreensaver\fP from your
647 session, so that the screensaver will run even when nobody is logged
650 The trick to using xscreensaver with \fIxdm\fP is this: keep in mind the
651 two very different states in which xscreensaver will be running:
654 .B 1: Nobody logged in.
656 If you're thinking of running xscreensaver from XDM at all, then it's
657 probably because you want graphics demos to be running on the console
658 when nobody is logged in there. In this case, xscreensaver will function
659 only as a screen saver, not a screen locker: it doesn't make sense
660 for xscreensaver to lock the screen, since nobody is logged in yet!
661 The only thing on the screen is the XDM login prompt.
663 .B 2: Somebody logged in.
665 Once someone has logged in through the XDM login window, the situation is
666 very different. For example: now it makes sense to lock the screen (and
667 prompt for the logged in user's password); and now xscreensaver should
668 consult that user's \fI~/.xscreensaver\fP file; and so on.
671 The difference between these two states comes down to a question of,
672 which user is the \fIxscreensaver\fP process running as? For the first
673 state, it doesn't matter. If you start \fIxscreensaver\fP in the usual
674 XDM way, then xscreensaver will probably end up running as root, which
675 is fine for the first case (the ``nobody logged in'' case.)
677 However, once someone is logged in, running as root is no longer fine:
678 because xscreensaver will be consulting root's \fI.xscreensaver\fP file
679 instead of that of the logged in user, and won't be prompting for the
680 logged in user's password, and so on. (This is not a security problem,
681 it's just not what you want.)
683 So, once someone has logged in, you want xscreensaver to be running as that
684 user. The way to accomplish this is to kill the old xscreensaver process
685 and start a new one (as the new user.)
687 The simplest way to accomplish all of this is as follows:
690 .B 1: Launch xscreensaver before anyone logs in.
692 To the file \fI/usr/lib/X11/xdm/Xsetup\fP, add the lines
695 xscreensaver-command -exit
698 This will run xscreensaver as root, over the XDM login window.
699 Moving the mouse will cause the screen to un-blank, and allow the user
700 to type their password at XDM to log in.
702 .B 2: Restart xscreensaver when someone logs in.
704 Near the top of the file \fI/usr/lib/X11/xdm/Xsession\fP, add those same lines:
706 xscreensaver-command -exit
709 When someone logs in, this will kill off the existing (root) xscreensaver
710 process, and start a new one, running as the user who has just logged in.
711 If the user's .xscreensaver file requests locking, they'll get it. They
712 will also get their own choice of timeouts, and graphics demos, and so on.
714 Alternately, each user could just put those lines in their
715 personal \fI~/.xsession\fP files.
718 Make sure you have \fB$PATH\fP set up correctly in the \fIXsetup\fP
719 and \fIXsession\fP scripts, or \fIxdm\fP won't be able to
720 find \fIxscreensaver\fP, and/or \fIxscreensaver\fP won't be able to
721 find its graphics demos.
723 (If your system does not seem to be executing the \fIXsetup\fP file, you
724 may need to configure it to do so: the traditional way to do this is
725 to make that file the value of the \fIDisplayManager*setup\fP resource
726 in the \fI/usr/lib/X11/xdm/xdm-config\fP file. See the man page for
730 It is safe to run \fIxscreensaver\fP as root (as \fIxdm\fP is likely to do.)
731 If run as root, \fIxscreensaver\fP changes its effective user and group ids
732 to something safe (like \fI"nobody"\fP) before connecting to the X server
733 or launching user-specified programs.
735 An unfortunate side effect of this (important) security precaution is that
736 it may conflict with cookie-based authentication.
738 If you get "connection refused" errors when running \fIxscreensaver\fP
739 from \fIxdm\fP, then this probably means that you have
741 or some other security mechanism turned on. One way around this is to
742 add \fB"xhost\ +localhost"\fP to \fIXsetup\fP, just before \fIxscreensaver\fP
745 Note that this will give access to the X server to anyone capable of logging
746 in to the local machine, so in some environments, this might not be
747 appropriate. If turning off file-system-based access control is not
748 acceptable, then running \fIxscreensaver\fP from the \fIXsetup\fP file
749 might not be possible, and xscreensaver will only work when running as
750 a normal, unprivileged user.
752 For more information on the X server's access control mechanisms, see the
760 The instructions for using \fIxscreensaver\fP with
762 are almost the same as for using
764 above. There are only two differences, really: instead
765 of editing \fI/usr/lib/X11/xdm/Xsetup\fP, edit the
766 file \fI/etc/X11/gdm/Init/Default\fP; and instead of
767 editing \fI/usr/lib/X11/xdm/Xsession\fP, edit one or all of the
768 files in the \fI/etc/X11/gdm/Sessions/\fP directory. (Note that
769 the default session (\fI/etc/X11/gdm/Sessions/Default\fP) usually
770 simply executes \fI/usr/lib/X11/xdm/Xsession\fP, so be careful
771 you aren't initializing xscreensaver twice.)
773 All the same caveats apply for
777 .SH USING CDE (COMMON DESKTOP ENVIRONMENT)
778 The easiest way to use \fIxscreensaver\fP on a system with CDE is to simply
779 switch off the built-in CDE screensaver, and use \fIxscreensaver\fP instead;
780 and second, to tell the front panel to run
781 .BR xscreensaver\-command (1)
782 with the \fI\-lock\fP option when the \fILock\fP icon is clicked.
784 To accomplish this involves five steps:
787 \fB1: Switch off CDE's locker\fP
788 Do this by turning off ``\fIScreen Saver and Screen Lock\fP'' in the
789 Screen section of the Style Manager.
791 \fB2: Edit sessionetc\fP
792 Edit the file \fI~/.dt/sessions/sessionetc\fP and add to it the line
796 This will cause \fIxscreensaver\fP to be launched when you log in.
797 (As always, make sure that xscreensaver and the graphics demos are on
798 your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
799 and/or \fI.dtprofile\fP, not \fI.login\fP.)
801 \fB3: Create XScreenSaver.dt\fP
802 Create a file called \fI~/.dt/types/XScreenSaver.dt\fP with the following
809 EXEC_STRING xscreensaver-command -lock
814 This defines a ``lock'' command for the CDE front panel, that knows how
815 to talk to \fIxscreensaver\fP.
817 \fB4: Create Lock.fp\fP
818 Create a file called \fI~/.dt/types/Lock.fp\fP with the following
824 CONTAINER_NAME Switch
825 CONTAINER_TYPE SWITCH
829 PUSH_ACTION XScreenSaver
830 HELP_TOPIC FPOnItemLock
834 This associates the CDE front panel ``Lock'' icon with the lock command
835 we just defined in step 3.
838 Select ``\fIRestart Workspace Manager\fP'' from the popup menu to make
839 your changes take effect. If things seem not to be working, check the
840 file \fI~/.dt/errorlog\fP for error messages.
842 .SH USING HP VUE (VISUAL USER ENVIRONMENT)
843 Since CDE is a descendant of VUE, the instructions for using xscreensaver
844 under VUE are similar to the above:
847 \fB1: Switch off VUE's locker\fP
848 Open the ``\fIStyle Manager\fP'' and select ``\fIScreen\fP.''
849 Turn off ``\fIScreen Saver and Screen Lock\fP'' option.
851 \fB2: Make sure you have a Session\fP
852 Next, go to the Style Manager's, ``\fIStartup\fP'' page.
853 Click on ``\fISet Home Session\fP'' to create a session, then
854 on ``\fIReturn to Home Session\fP'' to select this session each
857 \fB3: Edit vue.session\fP
858 Edit the file \fI~/.vue/sessions/home/vue.session\fP and add to it
861 vuesmcmd -screen 0 -cmd "xscreensaver"
863 This will cause \fIxscreensaver\fP to be launched when you log in.
864 (As always, make sure that xscreensaver and the graphics demos are on
865 your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
866 and/or \fI.profile\fP, not \fI.login\fP.)
868 \fB3: Edit vuewmrc\fP
869 Edit the file \fI~/.vue/vuewmrc\fP and add (or change) the Lock control:
875 PUSH_ACTION f.exec "xscreensaver-command -lock"
879 This associates the VUE front panel ``Lock'' icon with the xscreensaver
885 .BR xscreensaver-command (1)
886 program is a perfect candidate for something to add to your window manager's
887 popup menus. If you use
891 or (probably) any of \fItwm\fP's many descendants, you can do it like this:
894 \fB1. Create ~/.mwmrc (or ~/.twmrc or ...)\fP
895 If you don't have a \fI~/.mwmrc\fP file (or, on SGIs, a \fI~/.4Dwmrc\fP file;
896 or, with twm, a \fI~/.twmrc\fP file) then create one by making a copy of
897 the \fI/usr/lib/X11/system.mwmrc\fP
898 file (or \fI/usr/lib/X11/twm/system.twmrc\fP, and so on.)
900 \fB2. Add a menu definition.\fP
905 "Blank Screen Now" !"sleep 3; xscreensaver-command -activate"
906 "Lock Screen Now" !"sleep 3; xscreensaver-command -lock"
907 "Screen Saver Demo" !"xscreensaver-demo"
908 "Screen Saver Preferences" !"xscreensaver-demo -prefs"
909 "Reinitialize Screen Saver" !"xscreensaver-command -restart"
910 "Kill Screen Saver" !"xscreensaver-command -exit"
911 "Launch Screen Saver" !"xscreensaver &"
915 \fB3. Add the menu\fP
920 find the section of the file that says \fIMenu DefaultRootMenu\fP.
923 it will probably be \fImenu "defops"\fP. If you add a line somewhere
924 in that menu definition that reads
926 "XScreenSaver" f.menu XScreenSaver
928 then this will add an XScreenSaver sub-menu to your default root-window
929 popup menu. Alternately, you could just put the xscreensaver menu items
930 directly into the root menu.
933 For Fvwm2, the process is similar: first create a \fI~/.fvwm2rc\fP file
934 if you don't already have one, by making a copy of
935 the \fI/etc/X11/fvwm2/system.fvwm2rc\fP file. Then, add a menu definition
938 AddToMenu XScreenSaver "XScreenSaver" Title
939 + "Blank Screen Now" Exec xscreensaver-command -activate
940 + "Lock Screen Now" Exec xscreensaver-command -lock
941 + "Screen Saver Demo" Exec xscreensaver-command -demo
942 + "Screen Saver Preferences" Exec xscreensaver-command -prefs
943 + "Reinitialize Screen Saver" Exec xscreensaver-command -restart
944 + "Kill Screen Saver" Exec xscreensaver-command -exit
945 + "Launch Screen Saver" Exec xscreensaver
946 + "Run Next Demo" Exec xscreensaver-command -next
947 + "Run Previous Demo" Exec xscreensaver-command -prev
949 # To put the XScreenSaver sub-menu at the end of the root menu:
950 AddToMenu RootMenu "XScreenSaver" Popup XScreenSaver
952 The Enlightenment window manager keeps each of its menus in a separate
953 file. So, you need to create a file
954 named \fI~/.enlightenment/xscreensaver.menu\fP with the contents:
956 "XScreenSaver Commands"
957 "Blank Screen Now" NULL exec "xscreensaver-command -activate"
958 "Lock Screen Now" NULL exec "xscreensaver-command -lock"
959 "Screen Saver Demo" NULL exec "xscreensaver-command -demo"
960 "Screen Saver Prefs" NULL exec "xscreensaver-command -prefs"
961 "Reinitialize Saver" NULL exec "xscreensaver-command -restart"
962 "Kill Screen Saver" NULL exec "xscreensaver-command -exit"
963 "Launch Screen Saver" NULL exec "xscreensaver"
967 "XScreenSaver" NULL menu "xscreensaver.menu"
969 to \fI~/.enlightenment/file.menu\fP to put the XScreenSaver submenu on
970 your left-button root-window menu.
972 As you see, every window manager does this stuff gratuitously differently,
973 just to make your life difficult. You are in a maze of twisty menu
974 configuration languages, all alike.
976 Bugs? There are no bugs. Ok, well, maybe. If you find one, please let
977 me know. http://www.jwz.org/xscreensaver/bugs.html explains how to
978 construct the most useful bug reports.
981 If xscreensaver has been launched from
983 before anyone has logged in, you will need to kill and then restart the
984 xscreensaver daemon after you have logged in, or you will be confused by
985 the results. (For example, locking won't work, and your \fI~/.xscreensaver\fP
986 file will be ignored.)
988 When you are logged in, you want the \fIxscreensaver\fP daemon to be
989 running under \fIyour\fP user id, not as root or some other user.
991 If it has already been started by \fIxdm\fP, you can kill it by sending
992 it the \fBexit\fP command, and then re-launching it as you, by putting
993 something like the following in your personal X startup script:
995 xscreensaver-command -exit
998 The ``\fIUsing XDM(1)\fP'' section, above, goes into more detail, and explains
999 how to configure the system to do this for all users automatically.
1001 .B Locking and root logins
1002 In order for it to be safe for xscreensaver to be launched by \fIxdm\fP,
1003 certain precautions had to be taken, among them that xscreensaver never
1004 runs as \fIroot\fP. In particular, if it is launched as root (as \fIxdm\fP
1005 is likely to do), xscreensaver will disavow its privileges, and switch
1006 itself to a safe user id (such as \fInobody\fP.)
1008 An implication of this is that if you log in as \fIroot\fP on the console,
1009 xscreensaver will refuse to lock the screen (because it can't tell
1010 the difference between \fIroot\fP being logged in on the console, and a
1011 normal user being logged in on the console but xscreensaver having been
1017 The solution to this is simple: you shouldn't be logging in on the console
1018 as \fIroot\fP in the first place! (What, are you crazy or something?)
1020 Proper Unix hygiene dictates that you should log in as yourself, and
1022 to \fIroot\fP as necessary. People who spend their day logged in
1023 as \fIroot\fP are just begging for disaster.
1026 For xscreensaver to work when launched by
1028 programs running on the local machine as user \fI"nobody"\fP must be
1029 able to connect to the X server. This means that if you want to run
1030 xscreensaver on the console while nobody is logged in, you may need
1031 to disable cookie-based access control (and allow all users who can log
1032 in to the local machine to connect to the display.)
1034 You should be sure that this is an acceptable thing to do in your
1035 environment before doing it. See the ``\fIUsing XDM(1)\fP'' section,
1036 above, for more details.
1038 If anyone has suggestions on how xscreensaver could be made to work with
1040 without first turning off \fI.Xauthority\fP-based access control, please
1044 If you get an error message at startup like ``couldn't get password
1045 of \fIuser\fP'' then this probably means that you're on a system in which
1048 library routine can only be effectively used by root. If this is the case,
1049 then \fIxscreensaver\fP must be installed as setuid to root in order for
1050 locking to work. Care has been taken to make this a safe thing to do.
1052 It also may mean that your system uses shadow passwords instead of the standard
1054 interface; in that case, you may need to change some options
1055 with \fIconfigure\fP and recompile.
1057 If you change your password after xscreensaver has been launched, it will
1058 continue using your old password to unlock the screen until xscreensaver
1059 is restarted. So, after you change your password, you'll have to do
1061 xscreensaver-command -restart
1063 to make \fIxscreensaver\fP notice.
1066 If your system uses PAM (Pluggable Authentication Modules), then in order
1067 for xscreensaver to use PAM properly, PAM must be told about xscreensaver.
1068 The xscreensaver installation process should update the PAM data (on Linux,
1069 by creating the file \fI/etc/pam.d/xscreensaver\fP for you, and on Solaris,
1070 by telling you what lines to add to the \fI/etc/pam.conf\fP file.)
1072 If the PAM configuration files do not know about xscreensaver, then
1073 you \fImight\fP be in a situation where xscreensaver will refuse to ever
1076 This is a design flaw in PAM (there is no way for a client to tell the
1077 difference between PAM responding ``I have never heard of your module,''
1078 and responding, ``you typed the wrong password.'') As far as I can tell,
1079 there is no way for xscreensaver to automatically work around this, or
1080 detect the problem in advance, so if you have PAM, make sure it is
1081 configured correctly!
1083 .B Colormap lossage: TWM
1084 The \fBinstallColormap\fP option doesn't work very well with the
1086 window manager and its descendants.
1088 There is a race condition between the screensaver and this window manager,
1089 which can result in the screensaver's colormap not getting installed
1090 properly, meaning the graphics hacks will appear in essentially random
1091 colors. (If the screen goes white instead of black, this is probably why.)
1097 window managers don't have this problem. The race condition exists
1098 because X (really, ICCCM) does not provide a way for an OverrideRedirect
1099 window to have its own colormap, short of grabbing the server (which is
1100 neither a good idea, nor really possible with the current design.) What
1101 happens is that, as soon as xscreensaver installs its colormap, \fBtwm\fP
1102 responds to the resultant \fBColormapNotify\fP event by re-instaling the
1103 default colormap. Apparently, \fBtwm\fP doesn't \fIalways\fP do this; it
1104 seems to do it regularly if the screensaver is activated from a menu item,
1105 but seems to not do it if the screensaver comes on of its own volition, or
1106 is activated from another console.
1109 .B Attention, window manager authors!
1110 You should only call
1111 .BR XInstallColormap (3)
1112 in response to user events. That is, it is appropriate to install a colormap
1113 in response to \fBFocusIn\fP, \fBFocusOut\fP, \fBEnterNotify\fP,
1114 and \fBLeaveNotify\fP events; but it is not appropriate to call it in
1115 response to \fBColormapNotify\fP events. If you install colormaps in
1116 response to \fIapplication\fP actions as well as in response to \fIuser\fP
1117 actions, then you create the situation where it is impossible for
1118 override-redirect applications (such as xscreensaver) to display their
1119 windows in the proper colors.
1122 .B Colormap lossage: XV, XAnim, XEarth
1123 Some programs don't operate properly on visuals other than the default one,
1124 or with colormaps other than the default one. See the discussion of the
1125 magic "default-n" visual name in the description of the \fBprograms\fP
1126 resource in the \fIConfiguration\fP section. When programs only work with
1127 the default colormap, you need to use a syntax like this:
1129 default-n: xv -root image-1.gif -quit \\n\\
1130 default-n: xearth -nostars -wait 0 \\n\\
1132 It would also work to turn off the \fBinstallColormap\fP option altogether,
1133 but that would deny extra colors to those programs that \fIcan\fP take
1137 Although this program ``nices'' the subprocesses that it starts,
1138 graphics-intensive subprograms can still overload the machine by causing
1139 the X server process itself (which is not ``niced'') to suck a lot of
1140 cycles. Care should be taken to slow down programs intended for use as
1141 screensavers by inserting strategic calls to
1145 (or making liberal use of any \fI\-delay\fP options which the programs
1148 Note that the OpenGL-based graphics demos are real pigs on machines that
1149 don't have texture hardware.
1151 Also, an active screensaver will cause your X server to be pretty much
1152 permanently swapped in; but the same is true of any program that draws
1158 .B Latency and Responsiveness
1159 If the subprocess is drawing too quickly and the connection to the X
1160 server is a slow one (such as an X terminal running over a phone line) then
1161 the screensaver might not turn off right away when the user becomes active
1164 demo has this problem if being run in full-speed mode). This can be
1165 alleviated by inserting strategic calls to
1167 in code intended for use as a screensaver. This prevents too much graphics
1168 activity from being buffered up.
1170 .B XFree86's Magic Keystrokes
1171 The XFree86 X server traps certain magic keystrokes before client programs ever
1172 see them. Two that are of note are Ctrl+Alt+Backspace, which causes
1173 the X server to exit; and Ctrl+Alt+F\fIn\fP, which switches virtual consoles.
1174 The X server will respond to these keystrokes even if xscreensaver has the
1175 screen locked. Depending on your setup, you might consider this a problem.
1177 Unfortunately, there is no way for xscreensaver itself to override the
1178 interpretation of these keys. If you want to disable Ctrl+Alt+Backspace
1179 globally, you need to set the \fIDontZap\fP flag in
1180 your \fI/etc/X11/XF86Config\fP file. See the
1184 There is no way (as far as I can tell) to disable the VT-switching keystrokes.
1186 Some Linux systems come with a VT_LOCKSWITCH ioctl, that one could
1187 theoretically use to prevent VT-switching while the screen is locked;
1188 but unfortunately, this ioctl can only be used by root, which means
1189 that xscreensaver can't use it (since xscreensaver disavows its privileges
1190 shortly after startup, for security reasons.)
1192 Any suggestions for other solutions to this problem are welcome.
1195 Apparently there are some problems with XView programs getting confused
1196 and thinking that the screensaver window is the real root window even when
1197 the screensaver is not active: ClientMessages intended for the window manager
1198 are sent to the screensaver window instead. This could be solved by making
1199 xscreensaver forward all unrecognised ClientMessages to the real root window,
1200 but there may be other problems as well. If anyone has any insight on the
1201 cause of this problem, please let me know. (XView is an X11 toolkit that
1202 implements the (quite abominable) Sun OpenLook look-and-feel.)
1204 .B MIT Extension and Fading
1205 The \fBMIT-SCREEN-SAVER\fP extension is junk. Don't use it.
1207 When using the \fBMIT-SCREEN-SAVER\fP extension in conjunction with
1208 the \fBfade\fP option, you'll notice an unattractive flicker just before
1209 the fade begins. This is because the server maps a black window just before
1210 it tells the \fIxscreensaver\fP process to activate. The \fIxscreensaver\fP
1211 process immediately unmaps that window, but this results in a flicker. I
1212 haven't figured a way to get around this; it seems to be a fundamental
1213 property of the (mis-) design of this server extension.
1215 It sure would be nice if someone would implement the \fBSGI SCREEN_SAVER\fP
1216 extension in XFree86; it's dead simple, and works far better than the
1217 overengineered and broken \fBMIT-SCREEN-SAVER\fP extension.
1220 If you're running Irix 6.3, you might find that your monitor is powering down
1221 after an hour or two even if you've told it not to. This is fixed by SGI
1222 patches 2447 and 2537.
1224 If you're running Irix 6.5, this bug is back. I don't know a fix.
1226 .B MesaGL and Voodoo Cards
1227 If you have a 3Dfx/Voodoo card, the default settings for xscreensaver will
1228 run the GL-based graphics demos in such a way that they will not take
1229 advantage of the 3D acceleration hardware. The solution is to change
1230 the \fBprograms\fP entries for the GL hacks from this:
1236 MESA_GLX_FX=fullscreen gears \\n\\
1238 That is, make sure that \fB$MESA_GLX_FX\fP is set to \fIfullscreen\fP, and
1239 don't tell the program to draw on the root window. This may seem strange,
1240 but the setup used by Mesa and these kinds of cards \fIis\fP strange!
1242 For those who don't know, these cards work by sitting between your normal
1243 video card and the monitor, and seizing control of the monitor when it's
1244 time to do 3D. But this means that accelerated 3D only happens in full-screen
1245 mode (you can't do it in a window, and you can't see the output of 3D and 2D
1246 programs simultaniously), and that 3D will probably drive your monitor at a
1247 lower resolution, as well. It's bizarre.
1249 If you find that GL programs only work properly when run as root, and not
1250 as normal users, then the problem is that your \fI/dev/3dfx\fP file is not
1251 configured properly. Check the Linux 3Dfx FAQ.
1254 If \fIprocInterrupts\fP is on (which is the default on Linux systems) and
1255 you're using some program that toggles the state of your keyboard LEDs,
1256 xscreensaver won't work right: turning those LEDs on or off causes a
1257 keyboard interrupt, which xscreensaver will interpret as user activity.
1258 So if you're using such a program, set the \fIprocInterrupts\fP resource
1262 If you are not making use of one of the server extensions (\fBXIDLE\fP,
1263 \fBSGI SCREEN_SAVER\fP, or \fBMIT-SCREEN-SAVER\fP), then it is possible, in
1264 rare situations, for \fIxscreensaver\fP to interfere with event propagation
1265 and make another X program malfunction. For this to occur, that other
1266 application would need to \fInot\fP select \fBKeyPress\fP events on its
1267 non-leaf windows within the first 30 seconds of their existence, but then
1268 select for them later. In this case, that client \fImight\fP fail to receive
1269 those events. This isn't very likely, since programs generally select a
1270 constant set of events immediately after creating their windows and then
1271 don't change them, but this is the reason that it's a good idea to install
1272 and use one of the server extensions instead, to work around this shortcoming
1275 In all these years, I've not heard of even a single case of this happening,
1276 but it is theoretically possible, so I'm mentioning it for completeness...
1279 There need to be a lot more graphics hacks. In particular, there should be
1280 a simulation of a Lavalite (tm).
1285 to get the default host and display number, and to inform the sub-programs
1286 of the screen on which to draw.
1289 to find the sub-programs to run.
1292 for the directory in which to read and write the \fI.xscreensaver\fP file.
1295 to get the name of a resource file that overrides the global resources
1296 stored in the RESOURCE_MANAGER property.
1298 The latest version can always be found at
1299 http://www.jwz.org/xscreensaver/
1302 .BR xscreensaver\-demo (1),
1303 .BR xscreensaver\-command (1),
1304 .BR xscreensaver\-gl\-helper (1),
1325 .BR decayscreen (1),
1350 .BR interference (1),
1353 .BR kaleidescope (1),
1385 .BR slidescreen (1),
1396 .BR superquadrics (1),
1411 .BR xbouncebits (1),
1423 Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
1424 by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell
1425 this software and its documentation for any purpose is hereby granted without
1426 fee, provided that the above copyright notice appear in all copies and that
1427 both that copyright notice and this permission notice appear in supporting
1428 documentation. No representations are made about the suitability of this
1429 software for any purpose. It is provided "as is" without express or implied
1432 Jamie Zawinski <jwz@jwz.org>. Written in late 1991; first posted
1433 to comp.sources.x on 13-Aug-1992.
1435 Please let me know if you find any bugs or make any improvements.
1436 .SH ACKNOWLEDGEMENTS
1437 Thanks to Angela Goodman for the XScreenSaver logo.
1439 Thanks to the many people who have contributed graphics demos to the package.
1441 Thanks to David Wojtowicz for implementing \fIlockTimeout\fP.
1443 Thanks to Martin Kraemer for adding support for shadow passwords and
1444 locking-disabled diagnostics.
1446 Thanks to Patrick Moreau for the VMS port.
1448 Thanks to Mark Bowyer for figuring out how to hook it up to CDE.
1450 Thanks to Nat Lanza for the Kerberos support.
1452 Thanks to Bill Nottingham for the initial PAM support.
1454 And thanks to Jon A. Christopher for implementing the Athena dialog
1455 support, back in the days before Lesstif or Gtk were viable alternatives