.if n .sp 1
.if t .sp .5
..
-.TH XScreenSaver 1 "22-mar-93" "X Version 11"
+.TH XScreenSaver 1 "14-Aug-2004 (4.18)" "X Version 11"
.SH NAME
-xscreensaver - run graphics hacks after the user has been idle for a while
+xscreensaver - extensible screen saver framework, plus locking
.SH SYNOPSIS
.B xscreensaver
-[\-display \fIhost:display.screen\fP] [\-timeout \fIint\fP] [\-cycle \fIint\fP] [\-nice \fIint\fP] [\-verbose] [\-silent] [\-xidle] [\-no-xidle] [\-lock] [\-no-lock] [\-lock\-timeout \fIint\fP] [\-demo] [\-xrm \fIresources\fP]
+[\-display \fIhost:display.screen\fP] \
+[\-verbose] \
+[\-no\-capture\-stderr] \
+[\-no\-splash]
.SH DESCRIPTION
The \fIxscreensaver\fP program waits until the keyboard and mouse have been
idle for a period, and then runs a graphics demo chosen at random. It
This program can lock your terminal in order to prevent others from using it,
though its default mode of operation is merely to display pretty pictures on
-your screen when it is not in use.
+your screen when it is not in use.
-The benefit that this program has over the combination of the
-.BR xlock (1)
+It also provides configuration and control of your monitor's power-saving
+features.
+.SH GETTING STARTED
+For the impatient, try this:
+.EX
+xscreensaver &
+xscreensaver-demo
+.EE
+The
+.BR xscreensaver-demo (1)
+program pops up a dialog box that lets you configure the screen saver,
+and experiment with the various display modes.
+
+.B Note:
+unlike
+.BR xlock (1),
+xscreensaver has a client-server model: the \fIxscreensaver\fP program is a
+daemon that runs in the background; it is controlled by the foreground
+.BR xscreensaver-demo (1)
and
-.BR xautolock (1)
-programs is the ease with which new graphics hacks can be installed. You
-don't need to recompile (or even re-run) this program to add a new display
-mode.
-.SH OPTIONS
-.I xscreensaver
-accepts the following options:
+.BR xscreensaver-command (1)
+programs.
+.SH CONFIGURATION
+The easiest way to configure \fIxscreensaver\fP is to simply run the
+.BR xscreensaver-demo (1)
+program, and change the settings through the GUI. The rest of this
+manual page describes lower level ways of changing settings.
+
+I'll repeat that because it's important:
+
+.RS 4
+The easy way to configure xscreensaver is to run the
+.BR xscreensaver-demo (1)
+program. You shouldn't need to know any of the stuff described
+in \fIthis\fP manual unless you are trying to do something tricky,
+like customize xscreensaver for site-wide use or something.
+.RE
+
+Options to \fIxscreensaver\fP are stored in one of two places: in
+a \fI.xscreensaver\fP file in your home directory; or in the X resource
+database. If the \fI.xscreensaver\fP file exists, it overrides any settings
+in the resource database.
+
+The syntax of the \fI.xscreensaver\fP file is similar to that of
+the \fI.Xdefaults\fP file; for example, to set the \fItimeout\fP paramter
+in the \fI.xscreensaver\fP file, you would write the following:
+.EX
+timeout: 5
+.EE
+whereas, in the \fI.Xdefaults\fP file, you would write
+.EX
+xscreensaver.timeout: 5
+.EE
+If you change a setting in the \fI.xscreensaver\fP file while xscreensaver
+is already running, it will notice this, and reload the file. (The file will
+be reloaded the next time the screen saver needs to take some action, such as
+blanking or unblanking the screen, or picking a new graphics mode.)
+
+If you change a setting in your X resource database, or if you want
+xscreensaver to notice your changes immediately instead of the next time
+it wakes up, then you will need to reload your \fI.Xdefaults\fP file,
+and then tell the running xscreensaver process to restart itself, like so:
+.EX
+xrdb < ~/.Xdefaults
+xscreensaver-command -restart
+.EE
+If you want to set the system-wide defaults, then make your edits to
+the xscreensaver app-defaults file, which should have been installed
+when xscreensaver itself was installed. The app-defaults file will
+usually be named /usr/lib/X11/app-defaults/XScreenSaver, but different
+systems might keep it in a different place (for example,
+/usr/openwin/lib/app-defaults/XScreenSaver on Solaris.)
+
+When settings are changed in the Preferences dialog box (see above)
+the current settings will be written to the \fI.xscreensaver\fP file.
+(The \fI.Xdefaults\fP file and the app-defaults file will never be
+written by xscreensaver itself.)
+.PP
.TP 8
-.B \-timeout \fIminutes\fP
-The screensaver will activate after the keyboard and mouse have been idle
-for this many minutes.
+.B timeout\fP (class \fBTime\fP)
+The screensaver will activate (blank the screen) after the keyboard and
+mouse have been idle for this many minutes. Default 10 minutes.
.TP 8
-.B \-cycle \fIminutes\fP
+.B cycle\fP (class \fBTime\fP)
After the screensaver has been running for this many minutes, the currently
-running sub-process will be killed (with \fBSIGTERM\fP), and a new one
-started. If this is 0, then the sub-process will not be killed; only one
-demo will run until the screensaver is deactivated by user activity.
+running graphics-hack sub-process will be killed (with \fBSIGTERM\fP), and a
+new one started. If this is 0, then the graphics hack will never be changed:
+only one demo will run until the screensaver is deactivated by user activity.
+Default 10 minutes.
.TP 8
-.B \-nice \fIinteger\fP
-The sub-processes created by \fIxscreensaver\fP will be ``niced'' to this
-level, so that they do not consume cycles that are needed elsewhere.
+.B lock\fP (class \fBBoolean\fP)
+Enable locking: before the screensaver will turn off, it will require you
+to type the password of the logged-in user (really, the person who ran
+xscreensaver), or the root password. (\fBNote:\fP this doesn't work if the
+screensaver is launched by
+.BR xdm (1)
+because it can't know the user-id of the logged-in user. See
+the ``\fIUsing XDM(1)\fP'' section, below.
.TP 8
-.B \-verbose
-Print diagnostics.
+.B lockTimeout\fP (class \fBTime\fP)
+If locking is enabled, this controls the length of the ``grace period''
+between when the screensaver activates, and when the screen becomes locked.
+For example, if this is 5, and \fI\-timeout\fP is 10, then after 10 minutes,
+the screen would blank. If there was user activity at 12 minutes, no password
+would be required to un-blank the screen. But, if there was user activity
+at 15 minutes or later (that is, \fI\-lock\-timeout\fP minutes after
+activation) then a password would be required. The default is 0, meaning
+that if locking is enabled, then a password will be required as soon as the
+screen blanks.
+.TP 8
+.B passwdTimeout\fP (class \fBTime\fP)
+If the screen is locked, then this is how many seconds the password dialog box
+should be left on the screen before giving up (default 30 seconds.) This
+should not be too large: the X server is grabbed for the duration that the
+password dialog box is up (for security purposes) and leaving the server
+grabbed for too long can cause problems.
+.TP 8
+.B dpmsEnabled\fP (class \fBBoolean\fP)
+Whether power management is enabled.
+.TP 8
+.B dpmsStandby\fP (class \fBTime\fP)
+If power management is enabled, how long until the monitor goes solid black.
+.TP 8
+.B dpmsSuspend\fP (class \fBTime\fP)
+If power management is enabled, how long until the monitor goes into
+power-saving mode.
.TP 8
-.B \-silent
+.B dpmsOff\fP (class \fBTime\fP)
+If power management is enabled, how long until the monitor powers down
+completely. Note that these settings will have no effect unless both
+the X server and the display hardware support power management; not
+all do. See the \fIPower Management\fP section, below, for more
+information.
+.TP 8
+.B visualID\fP (class \fBVisualID\fP)
+Specify which X visual to use by default. (Note carefully that this resource
+is called \fBvisualID\fP, not merely \fBvisual\fP; if you set the \fBvisual\fP
+resource instead, things will malfunction in obscure ways for obscure reasons.)
+Legal values for the \fBVisualID\fP resource are:
+.RS 8
.TP 8
-.B \-xidle
-Use the \fIXIdle\fP server extension to decide whether the user is idle.
-This is the default if \fIxscreensaver\fP has been compiled with support
-for XIdle. The XIdle method is faster and more reliable than what will
-be done otherwise, so use it if you can.
+.B default
+Use the screen's default visual (the visual of the root window.)
+This is the default.
.TP 8
-.B \-no\-xidle
-Don't use \fIXIdle\fP.
+.B best
+Use the visual which supports the most colors. Note, however, that the
+visual with the most colors might be a TrueColor visual, which does not
+support colormap animation. Some programs have more interesting behavior
+when run on PseudoColor visuals than on TrueColor.
.TP 8
-.B \-lock
-Enable locking: before the screensaver will turn off, it requires you to
-type the password of the person who launched the screensaver, or the root
-password. (Note: this doesn't work if the screensaver is launched
-by
-.BR xdm (1)
-because it can't know the user-id of the logged-in user.)
-.TP 8
-.B \-no\-lock
-Disable locking. This is the default.
-.TP 8
-.B \-lock\-timeout \fIminutes\fP
-This is how long after the screensaver activates that locking is enabled.
-For example, if this is 5, then any user activity within five minutes of
-the time when the screensaver activated will cause the screen to unblank
-without requiring a password. After 5 minutes, a password will be
-required. The default is 0, meaning that if locking is enabled, then
-a password will be required as soon as the screensaver activates.
-.TP 8
-.B \-demo
-Enter the interactive demo mode immediately after startup. Normally
-demo mode is invoked via the
-.BR xscreensaver\-command (1)
-program.
-.SH X RESOURCES
-\fIxscreensaver\fP understands the following resources:
-.PP
+.B mono
+Use a monochrome visual, if there is one.
+.TP 8
+.B gray
+Use a grayscale or staticgray visual, if there is one and it has more than
+one plane (that is, it's not monochrome.)
+.TP 8
+.B color
+Use the best of the color visuals, if there are any.
+.TP 8
+.B GL
+Use the visual that is best for OpenGL programs. (OpenGL programs have
+somewhat different requirements than other X programs.)
+.TP 8
+.I class
+where \fIclass\fP is one of \fBStaticGray\fP, \fBStaticColor\fP,
+\fBTrueColor\fP, \fBGrayScale\fP, \fBPseudoColor\fP, or \fBDirectColor\fP.
+Selects the deepest visual of the given class.
.TP 8
-.B timeout \fR(class \fBTime\fP)
-Same as the \fI\-timeout\fP command-line option. Default 10 minutes.
+.I number
+where \fInumber\fP (decimal or hex) is interpreted as a visual id number,
+as reported by the
+.BR xdpyinfo (1)
+program; in this way you can have finer control over exactly which visual
+gets used, for example, to select a shallower one than would otherwise
+have been chosen.
+
+.RE
+.RS 8
+Note that this option specifies only the \fIdefault\fP visual that will
+be used: the visual used may be overridden on a program-by-program basis.
+See the description of the \fBprograms\fP resource, below.
+.RE
+.TP 8
+.B installColormap\fP (class \fBBoolean\fP)
+On PseudoColor (8-bit) displays, install a private colormap while the
+screensaver is active, so that the graphics hacks can get as many
+colors as possible. This is the default. (This only applies when the
+screen's default visual is being used, since non-default visuals get
+their own colormaps automatically.) This can also be overridden on a
+per-hack basis: see the discussion of the \fBdefault\-n\fP name in the
+section about the \fBprograms\fP resource.
+
+This does nothing if you have a TrueColor (16-bit or deeper) display.
+.TP 8
+.B verbose\fP (class \fBBoolean\fP)
+Whether to print diagnostics. Default false.
+.TP 8
+.B timestamp\fP (class \fBBoolean\fP)
+Whether to print the time of day along with any other diagnostic messages.
+Default true.
.TP 8
-.B cycle \fR(class \fBTime\fP)
-Same as the \fI\-cycle\fP command-line option. Default 10 minutes.
+.B splash\fP (class \fBBoolean\fP)
+Whether to display a splash screen at startup. Default true.
.TP 8
-.B nice \fR(class \fBNice\fP)
-Same as the \fI\-nice\fP command-line option. Default 10.
+.B splashDuration\fP (class \fBTime\fP)
+How long the splash screen should remain visible; default 5 seconds.
.TP 8
-.B verbose \fR(class \fBBoolean\fP)
-Same as the \fI\-verbose\fP command-line option.
+.B quad\fP (class \fBBoolean\fP)
+If true, then \fIfour\fP screensavers will be run on each monitor.
+Use at your own risk!
.TP 8
-.B xidle \fR(class \fBBoolean\fP)
-Same as the \fI\-xidle\fP command-line option.
+.B helpURL\fP (class \fBURL\fP)
+The splash screen has a \fIHelp\fP button on it. When you press it, it will
+display the web page indicated here in your web browser.
.TP 8
-.B lock \fR(class \fBBoolean\fP)
-Same as the \fI\-lock\fP command-line option.
+.B loadURL\fP (class \fBLoadURL\fP)
+This is the shell command used to load a URL into your web browser.
+The default setting will load it into Mozilla/Netscape if it is already
+running, otherwise, will launch a new browser looking at the \fIhelpURL\fP.
.TP 8
-.B lockTimeout \fR(class \fBTime\fP)
-Same as the \fI\-lock\-timeout\fP command-line option.
+.B demoCommand\fP (class \fBDemoCommand\fP)
+This is the shell command run when the \fIDemo\fP button on the splash window
+is pressed. It defaults to
+.BR xscreensaver\-demo (1).
+.TP 8
+.B prefsCommand\fP (class \fBPrefsCommand\fP)
+This is the shell command run when the \fIPrefs\fP button on the splash window
+is pressed. It defaults to \fIxscreensaver\-demo\ \-prefs\fP.
+.TP 8
+.B nice\fP (class \fBNice\fP)
+The sub-processes created by \fIxscreensaver\fP will be ``niced'' to this
+level, so that they are given lower priority than other processes on the
+system, and don't increase the load unnecessarily. The default is 10.
+
+(Higher numbers mean lower priority; see
+.BR nice (1)
+for details.)
.TP 8
-.B fade \fR(class \fBBoolean\fP)
+.B fade\fP (class \fBBoolean\fP)
If this is true, then when the screensaver activates, the current contents
of the screen will fade to black instead of simply winking out. This only
-works on displays with writable colormaps. Default true. A fade will also
-be done when switching graphics hacks (when the \fIcycle\fP timer expires.)
+works on certain systems. A fade will also be done when switching graphics
+hacks (when the \fIcycle\fP timer expires.) Default: true.
.TP 8
-.B unfade \fR(class \fBBoolean\fP)
+.B unfade\fP (class \fBBoolean\fP)
If this is true, then when the screensaver deactivates, the original contents
of the screen will fade in from black instead of appearing immediately. This
-only works on displays with writable colormaps, and if \fIfade\fP is true
-as well. Default false.
+only works on certain systems, and if \fIfade\fP is true as well.
+Default false.
.TP 8
-.B fadeSeconds \fR(class \fBTime\fP)
+.B fadeSeconds\fP (class \fBTime\fP)
If \fIfade\fP is true, this is how long the fade will be in
-seconds (default 1.)
+seconds (default 3 seconds.)
.TP 8
-.B fadeTicks \fR(class \fBInteger\fP)
+.B fadeTicks\fP (class \fBInteger\fP)
If \fIfade\fP is true, this is how many times a second the colormap will
be changed to effect a fade. Higher numbers yield smoother fades, but
-may make the fades take longer if your server isn't fast enough to keep
-up. Default 75.
-.TP 8
-.B installColormap \fR(class \fBBoolean\fP)
-Whether a new colormap should be installed while the screensaver is on,
-so that the graphics hacks can get as many colors as possible. Default
-false.
-.TP 8
-.B passwdTimeout \fR(class \fBTime\fP)
-If \fIlock\fP is true, this is how many seconds the password dialog box
-should be left on the screen before giving up (default 30.) This should
-not be too large: the X server is grabbed for the duration that the password
-dialog box is up (for security purposes) and leaving the server grabbed for
-too long can cause problems.
-.TP 8
-.B programs \fR(class \fBPrograms\fP)
+may make the fades take longer than the specified \fIfadeSeconds\fP if
+your server isn't fast enough to keep up. Default 20.
+.TP 8
+.B captureStderr\fP (class \fBBoolean\fP)
+Whether \fIxscreensaver\fP should redirect its stdout and stderr streams to
+the window itself. Since its nature is to take over the screen, you would not
+normally see error messages generated by xscreensaver or the sub-programs it
+runs; this resource will cause the output of all relevant programs to be
+drawn on the screensaver window itself, as well as being written to the
+controlling terminal of the screensaver driver process. Default true.
+.TP 8
+.B ignoreUninstalledPrograms\fP (class \fBBoolean\fP)
+There may be programs in the list that are not installed on the system,
+yet are marked as "enabled." If this preference is true, then such
+programs will simply be ignored. If false, then a warning will be printed
+if an attempt is made to run the nonexistent program. Also, the
+.BR xscreensaver-demo (1)
+program will suppress the non-existent programs from the list if this
+is true. Default: false.
+.TP 8
+.B font\fP (class \fBFont\fP)
+The font used for the stdout/stderr text, if \fBcaptureStderr\fP is true.
+Default \fB*\-medium\-r\-*\-140\-*\-m\-*\fP (a 14 point fixed-width font.)
+.TP 8
+.B mode\fP (class \fBMode\fP)
+Controls the behavior of xscreensaver. Legal values are:
+.RS 8
+.TP 8
+.B random
+When blanking the screen, select a random display mode from among those
+that are enabled and applicable. This is the default.
+.TP 8
+.B one
+When blanking the screen, only ever use one particular display mode (the
+one indicated by the \fIselected\fP setting.)
+.TP 8
+.B blank
+When blanking the screen, just go black: don't run any graphics hacks.
+.TP 8
+.B off
+Don't ever blank the screen, and don't ever allow the monitor to power down.
+
+.RE
+.TP 8
+.B selected\fP (class \fBInteger\fP)
+When \fImode\fP is set to \fIone\fP, this is the one, indicated by its
+index in the \fIprograms\fP list. You're crazy if you count them and
+set this number by hand: let
+.BR xscreensaver\-demo (1)
+do it for you!
+.TP 8
+.B programs\fP (class \fBPrograms\fP)
The graphics hacks which \fIxscreensaver\fP runs when the user is idle.
-The value of this resource is a string, one \fIsh\fP command per line.
-Each line must contain exactly one command -- no semicolons.
+The value of this resource is a multi-line string, one \fIsh\fP-syntax
+command per line. Each line must contain exactly one command: no
+semicolons, no ampersands.
+
+When the screensaver starts up, one of these is selected (according to
+the \fBmode\fP setting), and run. After the \fIcycle\fP period
+expires, it is killed, and another is selected and run.
-When the screensaver starts up, one of these is selected at random, and
-run. After the \fIcycle\fP period expires, it is killed, and another
-is selected and run.
+If a line begins with a dash (-) then that particular program is
+disabled: it won't be selected at random (though you can still select
+it explicitly using the
+.BR xscreensaver\-demo (1)
+program.)
-If the value of this resource (and the applicable one of \fBcolorPrograms\fP
-or \fBmonoPrograms\fP) is empty, then no programs will be run; the screen
-will simply be made black.
+If all programs are disabled, then the screen will just be made blank,
+as when \fImode\fP is set to \fIblank\fP.
+
+To disable a program, you must mark it as disabled with a dash instead
+of removing it from the list. This is because the system-wide (app-defaults)
+and per-user (.xscreensaver) settings are merged together, and if a user
+just \fIdeletes\fP an entry from their programs list, but that entry still
+exists in the system-wide list, then it will come back. However, if the
+user \fIdisables\fP it, then their setting takes precedence.
+
+If the display has multiple screens, then a different program will be run
+for each screen. (All screens are blanked and unblanked simultaniously.)
Note that you must escape the newlines; here is an example of how you
-might set this in your \fI.Xdefaults\fP file:
+might set this in your \fI~/.xscreensaver\fP file:
+
+.RS 8
.EX
-xscreensaver.programs: \\
- qix -root \\n\\
- ico -r -faces -sleep 1 -obj ico \\n\\
- xdaliclock -builtin2 -root \\n\\
- xwave -root
+programs: \\
+ qix -root \\n\\
+ ico -r -faces -sleep 1 -obj ico \\n\\
+ xdaliclock -builtin2 -root \\n\\
+ xv -root -rmode 5 image.gif -quit \\n
.EE
+.RE
+.RS 8
+Make sure your \fB$PATH\fP environment variable is set up correctly
+\fIbefore\fP xscreensaver is launched, or it won't be able to find the
+programs listed in the \fIprograms\fP resource.
+
To use a program as a screensaver, two things are required: that that
program draw on the root window (or be able to be configured to draw on
the root window); and that that program understand ``virtual root''
-windows, as used by virtual window managers such as \fItvtwm\fP.
+windows, as used by virtual window managers such as
+.BR tvtwm (1).
+(Generally, this is accomplished by just including the \fI"vroot.h"\fP
+header file in the program's source.)
-It is quite easy to make programs understand virtual roots if they
-don't already: you merely need to include the file \fI"vroot.h"\fP in
-them after the standard X includes, and recompile. This file is distributed
-with X11r5, and is included with xscreensaver as well.
+If there are some programs that you want to run only when using a color
+display, and others that you want to run only when using a monochrome
+display, you can specify that like this:
+.EX
+ mono: mono-program -root \\n\\
+ color: color-program -root \\n\\
+.EE
+.RE
+.RS 8
+More generally, you can specify the kind of visual that should be used for
+the window on which the program will be drawing. For example, if one
+program works best if it has a colormap, but another works best if it has
+a 24-bit visual, both can be accommodated:
+.EX
+ PseudoColor: cmap-program -root \\n\\
+ TrueColor: 24bit-program -root \\n\\
+.EE
+.RE
+.RS 8
+In addition to the symbolic visual names described above (in the discussion
+of the \fIvisualID\fP resource) one other visual name is supported in
+the \fIprograms\fP list:
+.RS 1
+.TP 4
+.B default-n
+This is like \fBdefault\fP, but also requests the use of the default colormap,
+instead of a private colormap. (That is, it behaves as if
+the \fI\-no\-install\fP command-line option was specified, but only for
+this particular hack.) This is provided because some third-party programs
+that draw on the root window (notably:
+.BR xv (1),
+and
+.BR xearth (1))
+make assumptions about the visual and colormap of the root window:
+assumptions which xscreensaver can violate.
+
+.RE
+If you specify a particular visual for a program, and that visual does not
+exist on the screen, then that program will not be chosen to run. This
+means that on displays with multiple screens of different depths, you can
+arrange for appropriate hacks to be run on each. For example, if one screen
+is color and the other is monochrome, hacks that look good in mono can be
+run on one, and hacks that only look good in color will show up on the other.
+.RE
+.PP
+.PP
+You shouldn't ever need to change the following resources:
+.PP
.TP 8
-.B monoPrograms \fR(class \fBMonoPrograms\fP)
-This resource is appended to the value of the \fIprograms\fP resource if
-the display on which the screensaver is running is monochrome.
+.B pointerPollTime\fP (class \fBTime\fP)
+When server extensions are not in use, this controls how
+frequently \fIxscreensaver\fP checks to see if the mouse position or buttons
+have changed. Default 5 seconds.
.TP 8
-.B colorPrograms \fR(class \fBColorPrograms\fP)
-This resource is appended to the value of the \fIprograms\fP resource if
-the display on which the screensaver is running is not monochrome.
+.B windowCreationTimeout\fP (class \fBTime\fP)
+When server extensions are not in use, this controls the delay between when
+windows are created and when \fIxscreensaver\fP selects events on them.
+Default 30 seconds.
+.TP 8
+.B initialDelay\fP (class \fBTime\fP)
+When server extensions are not in use, \fIxscreensaver\fP will wait this many
+seconds before selecting events on existing windows, under the assumption that
+\fIxscreensaver\fP is started during your login procedure, and the window
+state may be in flux. Default 0. (This used to default to 30, but that was
+back in the days when slow machines and X terminals were more common...)
+.RE
.PP
-Normally you won't need to change the following resources:
+There are a number of different X server extensions which can make
+xscreensaver's job easier. The next few resources specify whether these
+extensions should be utilized if they are available.
.TP 8
-.B bourneShell \fR(class \fBBourneShell\fP)
+.B sgiSaverExtension\fP (class \fBBoolean\fP)
+This resource controls whether the SGI \fBSCREEN_SAVER\fP server extension
+will be used to decide whether the user is idle. This is the default
+if \fIxscreensaver\fP has been compiled with support for this
+extension (which is the default on SGI systems.). If it is available,
+the \fBSCREEN_SAVER\fP method is faster and more reliable than what will
+be done otherwise, so use it if you can. (This extension is only available
+on Silicon Graphics systems, unfortunately.)
+.TP 8
+.B mitSaverExtension\fP (class \fBBoolean\fP)
+This resource controls whether the \fBMIT\-SCREEN\-SAVER\fP server extension
+will be used to decide whether the user is idle. However, the default for
+this resource is \fIfalse\fP, because even if this extension is available,
+it is flaky (and it also makes the \fBfade\fP option not work properly.)
+Use of this extension is not recommended.
+.TP 8
+.B xidleExtension\fP (class \fBBoolean\fP)
+This resource controls whether the \fBXIDLE\fP server extension will be
+used to decide whether the user is idle. This is the default
+if \fIxscreensaver\fP has been compiled with support for this extension.
+(This extension is only available for X11R4 and X11R5 systems, unfortunately.)
+.TP 8
+.B procInterrupts\fP (class \fBBoolean\fP)
+This resource controls whether the \fB/proc/interrupts\fP file should be
+consulted to decide whether the user is idle. This is the default
+if \fIxscreensaver\fP has been compiled on a system which supports this
+mechanism (i.e., Linux systems.)
+
+The benefit to doing this is that \fIxscreensaver\fP can note that the user
+is active even when the X console is not the active one: if the user is
+typing in another virtual console, xscreensaver will notice that and will
+fail to activate. For example, if you're playing Quake in VGA-mode,
+xscreensaver won't wake up in the middle of your game and start competing
+for CPU.
+
+The drawback to doing this is that perhaps you \fIreally do\fP want idleness
+on the X console to cause the X display to lock, even if there is activity
+on other virtual consoles. If you want that, then set this option to False.
+(Or just lock the X console manually.)
+
+The default value for this resource is True, on systems where it works.
+.TP 8
+.B overlayStderr\fP (class \fBBoolean\fP)
+If \fBcaptureStderr\fP is True, and your server supports ``overlay'' visuals,
+then the text will be written into one of the higher layers instead of into
+the same layer as the running screenhack. Set this to False to disable
+that (though you shouldn't need to.)
+.TP 8
+.B overlayTextForeground\fP (class \fBForeground\fP)
+The foreground color used for the stdout/stderr text, if \fBcaptureStderr\fP
+is true. Default: Yellow.
+.TP 8
+.B overlayTextBackground\fP (class \fBBackground\fP)
+The background color used for the stdout/stderr text, if \fBcaptureStderr\fP
+is true. Default: Black.
+.TP 8
+.B bourneShell\fP (class \fBBourneShell\fP)
The pathname of the shell that \fIxscreensaver\fP uses to start subprocesses.
-This must be whatever your local variant of \fB/bin/sh\fP is -- in particular,
+This must be whatever your local variant of \fB/bin/sh\fP is: in particular,
it must not be \fBcsh\fP.
+.SH COMMAND-LINE OPTIONS
+.I xscreensaver
+also accepts a few command-line options, mostly for use when debugging:
+for normal operation, you should configure things via the \fI~/.xscreensaver\fP
+file.
.TP 8
-.B windowCreationTimeout \fR(class \fBTime\fP)
-When \fIXIdle\fP is not in use, this controls the delay between when
-windows are created and when \fIxscreensaver\fP selects events on them.
-Default 30 seconds.
+.B \-display \fIhost:display.screen\fP
+The X display to use. For displays with multiple screens, XScreenSaver
+will manage all screens on the display simultaniously.
.TP 8
-.B pointerPollTime \fR(class \fBTime\fP)
-When \fIXIdle\fP is not in use, this controls how frequently \fIxscreensaver\fP
-checks to see if the mouse position or buttons have changed. Default 5 seconds.
+.B \-verbose
+Same as setting the \fIverbose\fP resource to \fItrue\fP: print diagnostics
+on stderr and on the xscreensaver window.
.TP 8
-.B initialDelay \fR(class \fBTime\fP)
-When \fIXIdle\fP is not in use, \fIxscreensaver\fP will wait this many seconds
-before selecting events on existing windows, under the assumption that
-\fIxscreensaver\fP is started during your login procedure, and the window
-state may be in flux. Default 30 seconds.
-.SH "HOW IT WORKS"
+.B \-no-capture-stderr
+Same as setting the \fIcaptureStderr\fP resource to \fIfalse\fP: do not
+redirect the stdout and stderr streams to the xscreensaver window itself.
+If xscreensaver is crashing, you might need to do this in order to see
+the error message.
+.SH HOW IT WORKS
When it is time to activate the screensaver, a full-screen black window is
-created. This window is given the appropriate properties so that, to any
-subsequently-created programs, it will appear to be a ``virtual root''
-window. Because of this, any program which draws on the root window (and
-which understands virtual roots) can be used as a screensaver.
-.PP
-When the user becomes active again, the screensaver window is unmapped and
-the running subprocess is killed by sending it \fBSIGTERM\fP. This is also
-how the subprocesses are killed when the screensaver decides that it's time
-to run a different demo: the old one is killed and a new one is launched.
-.PP
+created on each screen of the display. Each window is created in such a way
+that, to any subsequently-created programs, it will appear to be a ``virtual
+root'' window. Because of this, any program which draws on the root
+window (and which understands virtual roots) can be used as a screensaver.
+
+When the user becomes active again, the screensaver windows are unmapped, and
+the running subprocesses are killed by sending them \fBSIGTERM\fP. This is
+also how the subprocesses are killed when the screensaver decides that it's
+time to run a different demo: the old one is killed and a new one is launched.
+
Before launching a subprocess, \fIxscreensaver\fP stores an appropriate value
-for \fB$DISPLAY\fP in the environment that the child will recieve. (This is
+for \fB$DISPLAY\fP in the environment that the child will receive. (This is
so that if you start \fIxscreensaver\fP with a \fI-display\fP argument, the
-programs which \fIxscreensaver\fP launches will draw on the same display.)
-.PP
+programs which \fIxscreensaver\fP launches will draw on the same display;
+and so that the child will end up drawing on the appropriate screen of a
+multi-headed display.)
+
When the screensaver turns off, or is killed, care is taken to restore
the ``real'' virtual root window if there is one. Because of this, it is
important that you not kill the screensaver process with \fIkill -9\fP if
you are running a virtual-root window manager. If you kill it with \-9,
you may need to restart your window manager to repair the damage. This
isn't an issue if you aren't running a virtual-root window manager.
-.PP
+
For all the gory details, see the commentary at the top of xscreensaver.c.
-.PP
+
You can control a running screensaver process by using the
.BR xscreensaver\-command (1)
program (which see.)
+.SH POWER MANAGEMENT
+Modern X servers contain support to power down the monitor after an idle
+period. If the monitor has powered down, then \fIxscreensaver\fP will
+notice this (after a few minutes), and will not waste CPU by drawing
+graphics demos on a black screen. An attempt will also be made to
+explicitly power the monitor back up as soon as user activity is detected.
+
+As of version 3.28 (Feb 2001), the \fI~/.xscreensaver\fP file controls the
+configuration of your display's power management settings: if you have
+used
+.BR xset (1)
+to change your power management settings, then xscreensaver will
+override those changes with the values specified
+in \fI~/.xscreensaver\fP (or with its built-in defaults, if there
+is no \fI~/.xscreensaver\fP file yet.)
+
+To change your power management settings, run
+.BR xscreensaver\-demo (1)
+and change the various timeouts through the user interface.
+Alternately, you can edit the \fI~/.xscreensaver\fP file directly.
+
+If the power management section is grayed out in the
+.BR xscreensaver\-demo (1)
+window, then that means that your X server does not support
+the XDPMS extension, and so control over the monitor's power state
+is not available.
+
+If you're using a laptop, don't be surprised if changing the DPMS
+settings has no effect: many laptops have monitor power-saving behavior
+built in at a very low level that is invisible to Unix and X. On such
+systems, you can typically adjust the power-saving delays only by
+changing settings in the BIOS in some hardware-specific way.
+
+If DPMS seems not to be working with XFree86, make sure the "DPMS"
+option is set in your \fI/etc/X11/XF86Config\fP file. See the
+.BR XF86Config (5)
+manual for details.
+.SH USING XDM(1)
+You can run \fIxscreensaver\fP from your
+.BR xdm (1)
+session, so that the screensaver will run even when nobody is logged
+in on the console.
+
+The trick to using xscreensaver with \fIxdm\fP is this: keep in mind the
+two very different states in which xscreensaver will be running:
+.RS 4
+.TP 3
+.B 1: Nobody logged in.
+
+If you're thinking of running xscreensaver from XDM at all, then it's
+probably because you want graphics demos to be running on the console
+when nobody is logged in there. In this case, xscreensaver will function
+only as a screen saver, not a screen locker: it doesn't make sense
+for xscreensaver to lock the screen, since nobody is logged in yet!
+The only thing on the screen is the XDM login prompt.
+.TP 3
+.B 2: Somebody logged in.
+
+Once someone has logged in through the XDM login window, the situation is
+very different. For example: now it makes sense to lock the screen (and
+prompt for the logged in user's password); and now xscreensaver should
+consult that user's \fI~/.xscreensaver\fP file; and so on.
+.RE
+
+The difference between these two states comes down to a question of,
+which user is the \fIxscreensaver\fP process running as? For the first
+state, it doesn't matter. If you start \fIxscreensaver\fP in the usual
+XDM way, then xscreensaver will probably end up running as root, which
+is fine for the first case (the ``nobody logged in'' case.)
+
+However, once someone is logged in, running as root is no longer fine:
+because xscreensaver will be consulting root's \fI.xscreensaver\fP file
+instead of that of the logged in user, and won't be prompting for the
+logged in user's password, and so on. (This is not a security problem,
+it's just not what you want.)
+
+So, once someone has logged in, you want xscreensaver to be running as that
+user. The way to accomplish this is to kill the old xscreensaver process
+and start a new one (as the new user.)
+
+The simplest way to accomplish all of this is as follows:
+.RS 4
+.TP 3
+.B 1: Launch xscreensaver before anyone logs in.
+
+To the file \fI/usr/lib/X11/xdm/Xsetup\fP, add the lines
+.EX
+xhost +localhost
+xscreensaver-command -exit
+xscreensaver &
+.EE
+This will run xscreensaver as root, over the XDM login window.
+Moving the mouse will cause the screen to un-blank, and allow the user
+to type their password at XDM to log in.
+.TP 3
+.B 2: Restart xscreensaver when someone logs in.
+
+Near the top of the file \fI/usr/lib/X11/xdm/Xsession\fP, add those same lines:
+.EX
+xscreensaver-command -exit
+xscreensaver &
+.EE
+When someone logs in, this will kill off the existing (root) xscreensaver
+process, and start a new one, running as the user who has just logged in.
+If the user's .xscreensaver file requests locking, they'll get it. They
+will also get their own choice of timeouts, and graphics demos, and so on.
+
+Alternately, each user could just put those lines in their
+personal \fI~/.xsession\fP files.
+.RE
+
+Make sure you have \fB$PATH\fP set up correctly in the \fIXsetup\fP
+and \fIXsession\fP scripts, or \fIxdm\fP won't be able to
+find \fIxscreensaver\fP, and/or \fIxscreensaver\fP won't be able to
+find its graphics demos.
+
+(If your system does not seem to be executing the \fIXsetup\fP file, you
+may need to configure it to do so: the traditional way to do this is
+to make that file the value of the \fIDisplayManager*setup\fP resource
+in the \fI/usr/lib/X11/xdm/xdm-config\fP file. See the man page for
+.BR xdm (1)
+for more details.)
+
+It is safe to run \fIxscreensaver\fP as root (as \fIxdm\fP is likely to do.)
+If run as root, \fIxscreensaver\fP changes its effective user and group ids
+to something safe (like \fI"nobody"\fP) before connecting to the X server
+or launching user-specified programs.
+
+An unfortunate side effect of this (important) security precaution is that
+it may conflict with cookie-based authentication.
+
+If you get "connection refused" errors when running \fIxscreensaver\fP
+from \fIxdm\fP, then this probably means that you have
+.BR xauth (1)
+or some other security mechanism turned on. One way around this is to
+add \fB"xhost\ +localhost"\fP to \fIXsetup\fP, just before \fIxscreensaver\fP
+is launched.
+
+Note that this will give access to the X server to anyone capable of logging
+in to the local machine, so in some environments, this might not be
+appropriate. If turning off file-system-based access control is not
+acceptable, then running \fIxscreensaver\fP from the \fIXsetup\fP file
+might not be possible, and xscreensaver will only work when running as
+a normal, unprivileged user.
+
+For more information on the X server's access control mechanisms, see the
+man pages for
+.BR X (1),
+.BR Xsecurity (1),
+.BR xauth (1),
+and
+.BR xhost (1).
+.SH USING GDM(1)
+Using xscreensaver with
+.BR gdm (1)
+is easy, because gdm has a configuration tool. Just fire up
+.BR gdmconfig (1)
+and on the \fIBackground\fP page, type \fB"xscreensaver -nosplash"\fP into
+the \fIBackground Program\fP field. That will cause gdm to run xscreensaver
+while nobody is logged in, and kill it as soon as someone does log in.
+(The user will then be responsible for starting xscreensaver on their
+own, if they want.)
+
+Another way to accomplish the same thing is to edit the
+file \fI/etc/X11/gdm/gdm.conf\fP to include:
+.EX
+BackgroundProgram=xscreensaver -nosplash
+RunBackgroundProgramAlways=true
+.EE
+In this situation, the \fIxscreensaver\fP process will probably be running
+as user \fIgdm\fP instead of \fIroot\fP. You can configure the settings
+for this nobody-logged-in state (timeouts, DPMS, etc.) by editing
+the \fI~gdm/.xscreensaver\fP file.
+.SH USING KDE (K DESKTOP ENVIRONMENT)
+I understand that KDE has invented their own wrapper around xscreensaver,
+that is inferior to
+.BR xscreensaver-demo (1)
+in any number of ways. I've never actually seen it, but I'm told that
+this is the way you disable it:
+.RS 4
+.TP 3
+\fB1: Switch off KDE's screen saver.\fP
+Open the ``\fIControl Center\fP'' and
+select the ``\fILook and Feel / Screensaver\fP'' page.
+Turn off the ``\fIEnable Screensaver\fP'' checkbox.
+.TP 3
+\fB2: Find your Autostart directory.\fP
+Open the ``\fILook and Feel / Desktop / Paths\fP'' page,
+and see what your ``Autostart'' directory is set to: it will
+probably be \fI~/.kde3/Autostart/\fP or something similar.
+.TP 3
+\fB3: Make xscreensaver be an Autostart program.\fP
+Create a file in your autostart directory
+called \fIxscreensaver.desktop\fP that contains the following five lines:
+.EX
+[Desktop Entry]
+Exec=xscreensaver
+Name=XScreensaver
+Type=Application
+X-KDE-StartupNotify=false
+.EE
+.RE
+.PP
+Now use xscreensaver normally, controlling it via the usual
+.BR xscreensaver-demo (1)
+and
+.BR xscreensaver-command (1)
+mechanisms.
+.SH USING CDE (COMMON DESKTOP ENVIRONMENT)
+The easiest way to use \fIxscreensaver\fP on a system with CDE is to simply
+switch off the built-in CDE screensaver, and use \fIxscreensaver\fP instead;
+and second, to tell the front panel to run
+.BR xscreensaver\-command (1)
+with the \fI\-lock\fP option when the \fILock\fP icon is clicked.
+
+To accomplish this involves five steps:
+.RS 4
+.TP 3
+\fB1: Switch off CDE's locker\fP
+Do this by turning off ``\fIScreen Saver and Screen Lock\fP'' in the
+Screen section of the Style Manager.
+.TP 3
+\fB2: Edit sessionetc\fP
+Edit the file \fI~/.dt/sessions/sessionetc\fP and add to it the line
+.EX
+xscreensaver &
+.EE
+And make sure the sessionetc file is executable.
+This will cause \fIxscreensaver\fP to be launched when you log in.
+(As always, make sure that xscreensaver and the graphics demos are on
+your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
+and/or \fI.dtprofile\fP, not \fI.login\fP.)
+.TP 3
+\fB3: Create XScreenSaver.dt\fP
+Create a file called \fI~/.dt/types/XScreenSaver.dt\fP with the following
+contents:
+.EX
+ACTION XScreenSaver
+{
+ LABEL XScreenSaver
+ TYPE COMMAND
+ EXEC_STRING xscreensaver-command -lock
+ ICON Dtkey
+ WINDOW_TYPE NO_STDIO
+}
+.EE
+This defines a ``lock'' command for the CDE front panel, that knows how
+to talk to \fIxscreensaver\fP.
+.TP 3
+\fB4: Create Lock.fp\fP
+Create a file called \fI~/.dt/types/Lock.fp\fP with the following
+contents:
+.EX
+CONTROL Lock
+{
+ TYPE icon
+ CONTAINER_NAME Switch
+ CONTAINER_TYPE SWITCH
+ POSITION_HINTS 1
+ ICON Fplock
+ LABEL Lock
+ PUSH_ACTION XScreenSaver
+ HELP_TOPIC FPOnItemLock
+ HELP_VOLUME FPanel
+}
+.EE
+This associates the CDE front panel ``Lock'' icon with the lock command
+we just defined in step 3.
+.TP 3
+\fB5: Restart\fP
+Select ``\fIRestart Workspace Manager\fP'' from the popup menu to make
+your changes take effect. If things seem not to be working, check the
+file \fI~/.dt/errorlog\fP for error messages.
+.RE
+.SH USING HP VUE (VISUAL USER ENVIRONMENT)
+Since CDE is a descendant of VUE, the instructions for using xscreensaver
+under VUE are similar to the above:
+.RS 4
+.TP 3
+\fB1: Switch off VUE's locker\fP
+Open the ``\fIStyle Manager\fP'' and select ``\fIScreen\fP.''
+Turn off ``\fIScreen Saver and Screen Lock\fP'' option.
+.TP 3
+\fB2: Make sure you have a Session\fP
+Next, go to the Style Manager's, ``\fIStartup\fP'' page.
+Click on ``\fISet Home Session\fP'' to create a session, then
+on ``\fIReturn to Home Session\fP'' to select this session each
+time you log in.
+.TP 3
+\fB3: Edit vue.session\fP
+Edit the file \fI~/.vue/sessions/home/vue.session\fP and add to it
+the line
+.EX
+vuesmcmd -screen 0 -cmd "xscreensaver"
+.EE
+This will cause \fIxscreensaver\fP to be launched when you log in.
+(As always, make sure that xscreensaver and the graphics demos are on
+your \fB$PATH\fP; the path needs to be set in \fI.cshrc\fP
+and/or \fI.profile\fP, not \fI.login\fP.)
+.TP 3
+\fB3: Edit vuewmrc\fP
+Edit the file \fI~/.vue/vuewmrc\fP and add (or change) the Lock control:
+.EX
+CONTROL Lock
+{
+ TYPE button
+ IMAGE lock
+ PUSH_ACTION f.exec "xscreensaver-command -lock"
+ HELP_TOPIC FPLock
+}
+.EE
+This associates the VUE front panel ``Lock'' icon with the xscreensaver
+lock command.
+.RE
+.PP
+.SH BUGS
+Bugs? There are no bugs. Ok, well, maybe. If you find one, please let
+me know. http://www.jwz.org/xscreensaver/bugs.html explains how to
+construct the most useful bug reports.
+.TP 8
+.B Locking and XDM
+If xscreensaver has been launched from
+.BR xdm (1)
+before anyone has logged in, you will need to kill and then restart the
+xscreensaver daemon after you have logged in, or you will be confused by
+the results. (For example, locking won't work, and your \fI~/.xscreensaver\fP
+file will be ignored.)
+
+When you are logged in, you want the \fIxscreensaver\fP daemon to be
+running under \fIyour\fP user id, not as root or some other user.
+
+If it has already been started by \fIxdm\fP, you can kill it by sending
+it the \fBexit\fP command, and then re-launching it as you, by putting
+something like the following in your personal X startup script:
+.EX
+xscreensaver-command -exit
+xscreensaver &
+.EE
+The ``\fIUsing XDM(1)\fP'' section, above, goes into more detail, and explains
+how to configure the system to do this for all users automatically.
+.TP 8
+.B Locking and root logins
+In order for it to be safe for xscreensaver to be launched by \fIxdm\fP,
+certain precautions had to be taken, among them that xscreensaver never
+runs as \fIroot\fP. In particular, if it is launched as root (as \fIxdm\fP
+is likely to do), xscreensaver will disavow its privileges, and switch
+itself to a safe user id (such as \fInobody\fP.)
+
+An implication of this is that if you log in as \fIroot\fP on the console,
+xscreensaver will refuse to lock the screen (because it can't tell
+the difference between \fIroot\fP being logged in on the console, and a
+normal user being logged in on the console but xscreensaver having been
+launched by the
+.BR xdm (1)
+.I Xsetup
+file.)
+
+The solution to this is simple: you shouldn't be logging in on the console
+as \fIroot\fP in the first place! (What, are you crazy or something?)
+
+Proper Unix hygiene dictates that you should log in as yourself, and
+.BR su (1)
+to \fIroot\fP as necessary. People who spend their day logged in
+as \fIroot\fP are just begging for disaster.
+.TP 8
+.B XAUTH and XDM
+For xscreensaver to work when launched by
+.BR xdm (1),
+programs running on the local machine as user \fI"nobody"\fP must be
+able to connect to the X server. This means that if you want to run
+xscreensaver on the console while nobody is logged in, you may need
+to disable cookie-based access control (and allow all users who can log
+in to the local machine to connect to the display.)
+
+You should be sure that this is an acceptable thing to do in your
+environment before doing it. See the ``\fIUsing XDM(1)\fP'' section,
+above, for more details.
+.TP 8
+.B Passwords
+If you get an error message at startup like ``couldn't get password
+of \fIuser\fP'' then this probably means that you're on a system in which
+the
+.BR getpwent (3)
+library routine can only be effectively used by root. If this is the case,
+then \fIxscreensaver\fP must be installed as setuid to root in order for
+locking to work. Care has been taken to make this a safe thing to do.
+
+It also may mean that your system uses shadow passwords instead of the standard
+.BR getpwent (3)
+interface; in that case, you may need to change some options
+with \fIconfigure\fP and recompile.
+
+If you change your password after xscreensaver has been launched, it will
+continue using your old password to unlock the screen until xscreensaver
+is restarted. On some systems, it may accept \fIboth\fP your old and new
+passwords. So, after you change your password, you'll have to do
+.EX
+xscreensaver-command -restart
+.EE
+to make \fIxscreensaver\fP notice.
+.TP 8
+.B PAM Passwords
+If your system uses PAM (Pluggable Authentication Modules), then in order
+for xscreensaver to use PAM properly, PAM must be told about xscreensaver.
+The xscreensaver installation process should update the PAM data (on Linux,
+by creating the file \fI/etc/pam.d/xscreensaver\fP for you, and on Solaris,
+by telling you what lines to add to the \fI/etc/pam.conf\fP file.)
+
+If the PAM configuration files do not know about xscreensaver, then
+you \fImight\fP be in a situation where xscreensaver will refuse to ever
+unlock the screen.
+
+This is a design flaw in PAM (there is no way for a client to tell the
+difference between PAM responding ``I have never heard of your module,''
+and responding, ``you typed the wrong password.'') As far as I can tell,
+there is no way for xscreensaver to automatically work around this, or
+detect the problem in advance, so if you have PAM, make sure it is
+configured correctly!
+.TP 8
+.B Colormap lossage: TWM
+The \fBinstallColormap\fP option doesn't work very well with the
+.BR twm (1)
+window manager and its descendants, on 8-bit screens.
+
+There is a race condition between the screensaver and this window manager,
+which can result in the screensaver's colormap not getting installed
+properly, meaning the graphics hacks will appear in essentially random
+colors. (If the screen goes white instead of black, this is probably why.)
+
+The
+.BR mwm (1)
+and
+.BR olwm (1)
+window managers don't have this problem. The race condition exists
+because X (really, ICCCM) does not provide a way for an OverrideRedirect
+window to have its own colormap, short of grabbing the server (which is
+neither a good idea, nor really possible with the current design.) What
+happens is that, as soon as xscreensaver installs its colormap, \fBtwm\fP
+responds to the resultant \fBColormapNotify\fP event by re-instaling the
+default colormap. Apparently, \fBtwm\fP doesn't \fIalways\fP do this; it
+seems to do it regularly if the screensaver is activated from a menu item,
+but seems to not do it if the screensaver comes on of its own volition, or
+is activated from another console.
+.RS 8
+.TP 4
+.B Attention, window manager authors!
+You should only call
+.BR XInstallColormap (3)
+in response to user events. That is, it is appropriate to install a colormap
+in response to \fBFocusIn\fP, \fBFocusOut\fP, \fBEnterNotify\fP,
+and \fBLeaveNotify\fP events; but it is not appropriate to call it in
+response to \fBColormapNotify\fP events. If you install colormaps in
+response to \fIapplication\fP actions as well as in response to \fIuser\fP
+actions, then you create the situation where it is impossible for
+override-redirect applications (such as xscreensaver) to display their
+windows in the proper colors.
+.RE
+.TP 8
+.B Colormap lossage: XV, XAnim, XEarth
+Some programs don't operate properly on visuals other than the default one,
+or with colormaps other than the default one. See the discussion of the
+magic "default-n" visual name in the description of the \fBprograms\fP
+resource in the \fIConfiguration\fP section. When programs only work with
+the default colormap, you need to use a syntax like this:
+.EX
+ default-n: xv -root image-1.gif -quit \\n\\
+ default-n: xearth -nostars -wait 0 \\n\\
+.EE
+It would also work to turn off the \fBinstallColormap\fP option altogether,
+but that would deny extra colors to those programs that \fIcan\fP take
+advantage of them.
+.TP 8
+.B Machine Load
+Although this program ``nices'' the subprocesses that it starts,
+graphics-intensive subprograms can still overload the machine by causing
+the X server process itself (which is not ``niced'') to consume many
+cycles. Care has been taken in all the modules shipped with xscreensaver
+to sleep periodically, and not run full tilt, so as not to cause
+appreciable load.
+
+However, if you are running the OpenGL-based screen savers on a machine
+that does not have a video card with 3D acceleration, they \fIwill\fP
+make your machine slow, despite
+.BR nice (1).
+
+Your options are: don't use the OpenGL display modes; or, collect the
+spare change hidden under the cushions of your couch, and use it to
+buy a video card manufactured after 1998. (It doesn't even need to be
+\fIfast\fP 3D hardware: the problem will be fixed if there is any
+3D hardware \fIat all.\fP)
+.TP 8
+.B XFree86's Magic Keystrokes
+The XFree86 X server traps certain magic keystrokes before client programs ever
+see them. Two that are of note are Ctrl+Alt+Backspace, which causes
+the X server to exit; and Ctrl+Alt+F\fIn\fP, which switches virtual consoles.
+The X server will respond to these keystrokes even if xscreensaver has the
+screen locked. Depending on your setup, you might consider this a problem.
+
+Unfortunately, there is no way for xscreensaver itself to override the
+interpretation of these keys. If you want to disable Ctrl+Alt+Backspace
+globally, you need to set the \fIDontZap\fP flag in
+your \fI/etc/X11/XF86Config\fP file. To globally disable VT switching,
+you can set the \fIDontVTSwitch\fP flag. See the
+.BR XF86Config (5)
+manual for details.
+.TP 8
+.B MIT Extension and Fading
+The \fBMIT-SCREEN-SAVER\fP extension is junk. Don't use it.
+
+When using the \fBMIT-SCREEN-SAVER\fP extension in conjunction with
+the \fBfade\fP option, you'll notice an unattractive flicker just before
+the fade begins. This is because the server maps a black window just before
+it tells the \fIxscreensaver\fP process to activate. The \fIxscreensaver\fP
+process immediately unmaps that window, but this results in a flicker. I
+haven't figured a way to get around this; it seems to be a fundamental
+property of the (mis-) design of this server extension.
+
+It sure would be nice if someone would implement the \fBSGI SCREEN_SAVER\fP
+extension in XFree86; it's dead simple, and works far better than the
+overengineered and broken \fBMIT-SCREEN-SAVER\fP extension.
+.TP 8
+.B Keyboard LEDs
+If \fIprocInterrupts\fP is on (which is the default on Linux systems) and
+you're using some program that toggles the state of your keyboard LEDs,
+xscreensaver won't work right: turning those LEDs on or off causes a
+keyboard interrupt, which xscreensaver will interpret as user activity.
+So if you're using such a program, set the \fIprocInterrupts\fP resource
+to False.
+.TP 8
+.B Extensions
+If you are not making use of one of the server extensions (\fBXIDLE\fP,
+\fBSGI SCREEN_SAVER\fP, or \fBMIT-SCREEN-SAVER\fP), then it is possible, in
+rare situations, for \fIxscreensaver\fP to interfere with event propagation
+and make another X program malfunction. For this to occur, that other
+application would need to \fInot\fP select \fBKeyPress\fP events on its
+non-leaf windows within the first 30 seconds of their existence, but then
+select for them later. In this case, that client \fImight\fP fail to receive
+those events. This isn't very likely, since programs generally select a
+constant set of events immediately after creating their windows and then
+don't change them, but this is the reason that it's a good idea to install
+and use one of the server extensions instead, to work around this shortcoming
+in the X protocol.
+
+In all these years, I've not heard of even a single case of this happening,
+but it is theoretically possible, so I'm mentioning it for completeness...
.SH ENVIRONMENT
.PP
.TP 8
.B DISPLAY
-to get the default host and display number.
+to get the default host and display number, and to inform the sub-programs
+of the screen on which to draw.
+.TP 8
+.B PATH
+to find the sub-programs to run.
+.TP 8
+.B HOME
+for the directory in which to read the \fI.xscreensaver\fP file.
.TP 8
.B XENVIRONMENT
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.
-.SH USING XDM(1)
-You can run \fIxscreensaver\fP from your xdm session, so that the
-screensaver will run even when nobody is logged in on the console.
-Simply add \fB"xscreensaver &"\fP to your \fI/usr/lib/X11/xdm/Xsetup\fP
-file. Because \fIxdm\fP grabs the keyboard, keypresses will not make
-the screensaver deactivate, but any mouse activity will.
-.PP
-Users may want to add \fB"xscreensaver-command -restart"\fP to their
-startup scripts, so that the screensaver will be reinitialized with
-their private resource settings when they log in.
-.PP
-It is safe to run this program as root (as \fIxdm\fP is likely to do.) If
-run as root, \fIxscreensaver\fP changes its effective user and group ids to
-something safe (like \fI"nobody"\fP) before connecting to the X server
-or launching user-specified programs.
-.PP
-Locking doesn't work if the screensaver is launched by \fIxdm\fP. To get
-around this, you can run the screensaver from \fIxdm\fP without locking,
-and kill and restart it from your personal X startup script to enable
-locking.
-.SH DEMO MODE
-If \fIxscreensaver\fP receives the \fBDEMO\fP ClientMessage, it pops up
-a dialog box from which you can examine and experiment with the screensaver's
-client programs.
-.PP
-Clicking left on an element in the scrolling list will place the indicated
-program and its args in the text field to be edited. Edit the arguments and
-hit return to run the program with the parameters you have specified.
-.PP
-Double-clicking on an element in the scrolling list will run the indicated
-program immediately.
-.PP
-When a client program is launched, the dialog box is hidden. Clicking
-any mouse button will re-expose the dialog box (but will not kill the
-client program.)
-.TP 8
-.B Run Next
-Clicking this button will run the next program in the list after the
-currently-selected one, and will scroll around to the top when it reaches
-the bottom.
-.TP 8
-.B Run Previous
-Opposite of Run Next; at the top, it scrolls around to the bottom.
-.TP 8
-.B Edit Parameters
-This pops up a second dialog box, in which you have the option to
-interactively change most of the screensaver's operational parameters,
-such as its timeouts, and whether it should hack colormaps. Changing
-these parameters here will affect only the running \fIxscreensaver\fP
-process; to make the changes permanent, you need to edit your X resource
-file.
-.TP 8
-.B Exit Demo Mode
-Returns to normal screensaver operation.
-.TP 8
-.B Reinitialize
-Causes the screensaver process to exit and then restart with the same
-command-line arguments. This causes the X resource database to be
-re-read. This is just like the \fI\-restart\fP argument to
-.BR xscreensaver\-command (1)
-except that when executed from this button, the screensaver will
-automatically return to demo mode after restarting.
+.SH UPGRADES
+The latest version of xscreensaver, an online version of this manual,
+and a FAQ can always be found at http://www.jwz.org/xscreensaver/
.SH SEE ALSO
.BR X (1),
+.BR Xsecurity (1),
+.BR xauth (1),
+.BR xscreensaver\-demo (1),
.BR xscreensaver\-command (1),
-.BR xlock (1),
-.BR xnlock (1),
-.BR xautolock (1),
+.BR xscreensaver\-gl\-helper (1),
+.BR xscreensaver\-getimage (1),
.BR xdm (1),
-.BR qix (1),
-.BR pyro (1),
-.BR helix (1),
-.BR rorschach (1),
-.BR hopalong (1),
+.BR gdm (1),
+.BR xset (1),
+.BR xhost (1).
+.BR anemone (1),
+.BR ant (1),
+.BR apollonian (1),
+.BR atlantis (1),
.BR attraction (1),
-.BR greynetic (1),
-.BR rocks (1),
-.BR noseguy (1),
+.BR barcode (1),
+.BR blaster (1),
.BR blitspin (1),
-.BR imsmap (1),
-.BR slidescreen (1),
+.BR bouboule (1),
+.BR boxed (1),
+.BR braid (1),
+.BR bsod (1),
+.BR bubble3d (1),
+.BR bubbles (1),
+.BR bumps (1),
+.BR cage (1),
+.BR ccurve (1),
+.BR circuit (1),
+.BR compass (1),
+.BR coral (1),
+.BR cosmos (1),
+.BR critical (1),
+.BR crystal (1),
+.BR cubenetic (1),
+.BR cynosure (1),
+.BR dangerball (1),
+.BR decayscreen (1),
+.BR deco (1),
+.BR deluxe (1),
+.BR demon (1),
+.BR discrete (1),
+.BR distort (1),
+.BR drift (1),
+.BR electricsheep (1),
+.BR endgame (1),
+.BR engine (1),
+.BR epicycle (1),
+.BR eruption (1),*
+.BR euler2d (1),
+.BR extrusion (1),
+.BR fadeplot (1),
+.BR flag (1),
+.BR flame (1),
+.BR flipscreen3d (1),
+.BR flow (1),
+.BR fluidballs (1),
+.BR flurry (1),
+.BR forest (1),
+.BR galaxy (1),
+.BR gears (1),
+.BR gflux (1),
+.BR glblur (1),
+.BR glforestfire (1),
+.BR glplanet (1),
+.BR glsnake (1),
+.BR gltext (1),
+.BR goban (1),
+.BR goop (1),
+.BR grav (1),
+.BR greynetic (1),
+.BR halftone (1),
+.BR halo (1),
+.BR helix (1),
+.BR hopalong (1),
+.BR hyperball (1),
.BR hypercube (1),
+.BR ifs (1),
+.BR imsmap (1),
+.BR interference (1),
+.BR jigsaw (1),
+.BR juggle (1),
+.BR julia (1),
+.BR kaleidescope (1),
+.BR kumppa (1),
+.BR lament (1),
+.BR laser (1),
+.BR lavalite (1),
+.BR lightning (1),
+.BR lisa (1),
+.BR lissie (1),
+.BR lmorph (1),
+.BR loop (1),
.BR maze (1),
-.BR ico (1),
+.BR menger (1),
+.BR metaballs (1),
+.BR moebius (1),
+.BR moire (1),
+.BR moire2 (1),
+.BR molecule (1),
+.BR morph3d (1),
+.BR mountain (1),
+.BR munch (1),
+.BR nerverot (1),
+.BR noseguy (1),
+.BR pedal (1),
+.BR penetrate (1),
+.BR penrose (1),
+.BR petri (1),
+.BR phosphor (1),
+.BR pipes (1),
+.BR polyominoes (1),
+.BR popsquares (1),
+.BR pulsar (1),
+.BR pyro (1),
+.BR qix (1),
+.BR queens (1),
+.BR rd-bomb (1),
+.BR ripples (1),
+.BR rocks (1),
+.BR rorschach (1),
+.BR rotor (1),
+.BR rotzoomer (1),
+.BR rubik (1),
+.BR sballs (1),
+.BR shadebobs (1),
+.BR sierpinski (1),
+.BR sierpinski3d (1),
+.BR slidescreen (1),
+.BR slip (1),
+.BR sonar (1),
+.BR speedmine (1),
+.BR sphere (1),
+.BR sphereEversion (1),
+.BR spheremonics (1),
+.BR spiral (1),
+.BR spotlight (1),
+.BR sproingies (1),
+.BR squiral (1),
+.BR ssystem (1),
+.BR stairs (1),
+.BR starfish (1),
+.BR starwars (1),
+.BR stonerview (1),
+.BR strange (1),
+.BR superquadrics (1),
+.BR swirl (1),
+.BR t3d (1),
+.BR thornbird (1),
+.BR triangle (1),
+.BR truchet (1),
+.BR twang (1),
+.BR vermiculate (1),
+.BR vidwhacker (1),
+.BR vines (1),
+.BR wander (1),
+.BR webcollage (1),
+.BR whirlwindwarp (1),
+.BR whirlygig (1),
+.BR worm (1),
+.BR xaos (1),
.BR xdaliclock (1),
-.BR xbouncebits (1),
-.BR xswarm (1),
-.BR xwave (1),
-.BR xfishtank (1)
-.SH BUGS
-If you are not using \fIXIdle\fP, and an application does not
-select \fBKeyPress\fP events on its non-leaf windows within the first
-30 seconds of their existence, but selects them later, then it is
-possible that \fIxscreensaver\fP could interfere with the propagation
-of those events. This isn't very likely, but this is the reason that
-it's a good idea to install the \fIXIdle\fP extension.
-.PP
-Although this program ``nices'' the subprocesses that it starts,
-graphics-intensive subprograms can still overload the machine by causing
-the X server process itself (which is not ``niced'') to suck a lot of
-cycles. Care should be taken to slow down programs intended for use as
-screensavers by inserting strategic calls to
-.BR sleep (3)
-or
-.BR usleep (3)
-\.
-
-Also, it will cause your X server to be pretty much permanently swapped in.
-(but the same is true of any program that draws periodically, like xclock or
-xload.)
-.PP
-If the subprocess is drawing too quickly and the connection to the X
-server is a slow one (such as an X terminal running over a phone line) then
-the screensaver might not turn off right away when the user becomes active
-again (the
-.BR ico (1)
-demo has this problem if being run in full-speed mode). This can be
-alleviated by inserting strategic calls to
-.BR XSync (3)
-in code intended for use as a screensaver. This prevents too much graphics
-activity from being buffered up.
-.PP
-The screensaver only runs on the default screen of the display. If you have
-more than one screen, you must run multiple screensaver processes, one for
-each screen. (I don't actually know whether this works, because I don't
-have access to a multi-screen machine. Comments welcome.)
-.PP
-If you don't have Motif, you can't compile with support for locking or
-demo mode.
-.PP
-When the \fBRun Next\fP and \fBRun Previous\fP buttons are used, the selected
-item may not be visible in the window. It's a Motif bug that selecting a
-different item doesn't scroll the list to show the new selected item.
-.PP
-Locking doesn't work if the screensaver is launched by \fIxdm\fP.
-.PP
-If you get an error message like ``couldn't get password of foo'' then
-this probably means that you're on a system in which the
-.BR getpwent (3)
-library routine can only be effectively used by root. If this is the case,
-then \fIxscreensaver\fP must be installed as setuid to root. Care has
-been taken to make this a safe thing to do.
-.PP
-There need to be a lot more graphics hacks. In particular, there should be
-a simulation of a Lavalite (tm).
-.PP
-The \fBinstallColormap\fP option doesn't work very well with the
-.BR twm (1)
-window manager and its descendants. There is a race condition between the
-screensaver and this window manager, which can result in the screensaver's
-colormap not getting installed properly, meaning the graphics hacks will
-appear in essentially random colors. The
-.BR mwm (1)
-and
-.BR olwm (1)
-window managers don't seem to have this problem. The race condition exists
-because X apparently does not provide a way for an OverrideRedirect window to
-have its own colormap, short of grabbing the server (which is neither a good
-idea, nor really possible with the current design.) What happens is that, as
-soon as the screensaver installs its colormap, \fBtwm\fP responds to
-the \fBColormapNotify\fP event that is generated by re-instaling the default
-colormap. Apparently, \fBtwm\fP doesn't \fIalways\fP do this; it seems to do
-it regularly if the screensaver is activated from a menu item, but seems to
-not do it if the screensaver comes on of its own volition, or is activated
-from another console. Any thoughts on this problem are welcome...
-.PP
-The \fBinstallColormap\fP option has no effect in "demo" mode, since the
-dialog boxes allocate their colors out of the screen's default colormap
-instead of the installed colormap.
-.PP
-For this same reason, locking doesn't work too well along
-with \fBinstallColormap\fP; the dialog box's colors are random.
-.PP
-Apparently there are some problems with ``XView'' programs getting confused
-and thinking that the screensaver window is the real root window even when
-the screensaver is not active: ClientMessages intended for the window manager
-are sent to the screensaver window instead. This could be solved by making
-xscreensaver forward all unrecognised ClientMessages to the real root window,
-but there may be other problems as well.
+.BR xearth (1),
+.BR xfishtank (1),
+.BR xflame (1),
+.BR xjack (1),
+.BR xlyap (1),
+.BR xmatrix (1),
+.BR xmountains (1),
+.BR xrayswarm (1),
+.BR xsnow (1),
+.BR xspirograph (1),
+.BR xteevee (1),
+.BR zoom (1)
.SH COPYRIGHT
-Copyright \(co 1992, 1993 by Jamie Zawinski. Permission to use, copy, modify,
-distribute, and sell this software and its documentation for any purpose is
-hereby granted without fee, provided that the above copyright notice appear
-in all copies and that both that copyright notice and this permission notice
-appear in supporting documentation. No representations are made about the
-suitability of this software for any purpose. It is provided "as is" without
-express or implied warranty.
+Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+2000, 2001, 2002, 2003, 2004 by Jamie Zawinski. Permission to use, copy,
+modify, distribute, and sell this software and its documentation for
+any purpose is hereby granted without fee, provided that the above
+copyright notice appear in all copies and that both that copyright
+notice and this permission notice appear in supporting documentation.
+No representations are made about the suitability of this software for
+any purpose. It is provided "as is" without express or implied
+warranty.
.SH AUTHOR
-Jamie Zawinski <jwz@lucid.com>, 13-aug-92.
+Jamie Zawinski <jwz@jwz.org>. Written in late 1991; version 1.0 posted
+to comp.sources.x on 17-Aug-1992.
+
Please let me know if you find any bugs or make any improvements.
+.SH ACKNOWLEDGEMENTS
+Thanks to Angela Goodman for the XScreenSaver logo.
+
+Thanks to the many people who have contributed graphics demos to the package.
Thanks to David Wojtowicz for implementing \fIlockTimeout\fP.
+
+Thanks to Martin Kraemer for adding support for shadow passwords and
+locking-disabled diagnostics.
+
+Thanks to Patrick Moreau for the VMS port.
+
+Thanks to Nat Lanza for the Kerberos support.
+
+Thanks to Bill Nottingham for the initial PAM support.
+
+And thanks to Jon A. Christopher for implementing the Athena dialog
+support, back in the days before Lesstif or Gtk were viable alternatives
+to Motif.
projects / xscreensaver / blobdiff