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+.de EX \"Begin example
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.if n .sp 1
.if t .sp .5
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..
-.TH XScreenSaver 1 "31-May-97" "X Version 11"
+.TH XScreenSaver 1 "27-Apr-99 (3.10)" "X Version 11"
.SH NAME
xscreensaver - graphics hack and screen locker, launched when the user is idle
.SH SYNOPSIS
.B xscreensaver
-[\-display \fIhost:display.screen\fP] [\-timeout \fIint\fP] [\-cycle \fIint\fP] [\-nice \fIint\fP] [\-lock] [\-no\-lock] [\-lock\-timeout \fIint\fP] [\-demo] [\-visual \fIvisual\fP] [\-install] [\-no\-install] [\-verbose] [\-silent] [\-xidle\-extension] [\-no\-xidle\-extension] [\-sgi\-extension] [\-no\-sgi\-extension] [\-mit\-extension] [\-no\-mit\-extension] [\-xrm \fIresources\fP]
+[\-display \fIhost:display.screen\fP] \
+[\-timeout \fIint\fP] \
+[\-cycle \fIint\fP] \
+[\-lock\-mode] \
+[\-no\-lock\-mode] \
+[\-lock\-timeout \fIint\fP] \
+[\-visual \fIvisual\fP] \
+[\-install] \
+[\-no\-install] \
+[\-verbose] \
+[\-silent] \
+[\-timestamp] \
+[\-capture\-stderr] \
+[\-no\-capture\-stderr] \
+[\-splash] \
+[\-no\-splash] \
+[\-nice \fIint\fP] \
+[\-mit\-extension] \
+[\-no\-mit\-extension] \
+[\-sgi\-extension] \
+[\-no\-sgi\-extension] \
+[\-xidle\-extension] \
+[\-no\-xidle\-extension] \
+[\-proc\-interrupts] \
+[\-no\-proc\-interrupts] \
+[\-xrm \fIresources\fP]
.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
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 command line options:
+.SH GETTING STARTED
+For the impatient, try this:
+.EX
+xscreensaver &
+xscreensaver-demo
+.EE
+The
+.BR xscreensaver-demo (1)
+program should pop up a dialog box that lets you experiment with the
+xscreensaver settings and graphics 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 xscreensaver-command (1)
+programs.
+.SH CONFIGURATION
+Options to \fIxscreensaver\fP are specified 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 tell the running xscreensaver process
+to re-initialize itself, like so:
+.EX
+xscreensaver-command -restart
+.EE
+Note that if you changed the \fI.Xdefaults\fP file, you might also need to run
+.BR xrdb (1):
+.EX
+xrdb < ~/.Xdefaults
+.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. Default 10.
+.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 graphics hack sub-process will be killed (with \fBSIGTERM\fP), and a
-new one started. If this is 0, then the graphics hack will not be changed:
+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.
+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 are given lower priority than other processes on the
-system, and don't increase the load unnecessarily. The default is 20.
-
-(Higher numbers mean lower priority; see
-.BR nice (1)
-for details.)
-.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
+.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.)
-.TP 8
-.B \-no\-lock
-Disable locking. This is the default.
+because it can't know the user-id of the logged-in user. See
+the ``\fIUsing XDM(1)\fP'' section, below.
.TP 8
-.B \-lock\-timeout \fIminutes\fP
-This is how long after the screensaver activates that locking is enabled.
+.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. But, if there was user activity at 15 minutes or later
-(\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 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, but this is a shortcut for new users. See below for a description
-of how demo-mode works.
+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 \-visual \fIvisual\fP
-Specify which X visual to use by default. Legal values are:
+.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 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 default
.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.
+support colormap animation. Some programs have more interesting behavior
+when run on PseudoColor visuals than on TrueColor.
.TP 8
.B mono
Use a monochrome visual, if there is one.
Use the best of the color visuals, if there are any.
.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.
+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
.I number
where \fInumber\fP (decimal or hex) is interpreted as a visual id number,
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
-.PP
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 \-install
-When using a non-default visual, 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.)
-.TP 8
-.B \-no\-install
-Use the default colormap.
-.TP 8
-.B \-verbose
-Print diagnostics.
-.TP 8
-.B \-silent
-
-.TP 8
-.B \-xidle\-extension
-Use the \fBXIDLE\fP server extension to decide whether the user is idle.
-This is the default if \fIxscreensaver\fP has been compiled with support
-for this extension. On X11R4 or X11R5 systems, the XIdle method is faster
-and more reliable than what will be done otherwise, so use it if you can.
-.TP 8
-.B \-no\-xidle\-extension
-Don't use the \fBXIDLE\fP server extension.
-.TP 8
-.B \-sgi\-extension
-Use the SGI \fBSCREEN_SAVER\fP server extension 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.
-.TP 8
-.B \-no\-sgi\-extension
-Don't use the SGI \fBSCREEN_SAVER\fP server extension.
-.TP 8
-.B \-mit\-extension
-Use the \fBMIT\-SCREEN\-SAVER\fP server extension to decide whether the user
-is idle. This is the default if \fIxscreensaver\fP has been compiled with
-support for this extension. However, this extension is flaky, so it's use
-is not really recommended. (It also makes the \fIfade\fP option not work
-properly.)
+.B installColormap\fP (class \fBBoolean\fP)
+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.
.TP 8
-.B \-no\-mit\-extension
-Don't use the \fBMIT\-SCREEN\-SAVER\fP server extension.
-.SH X RESOURCES
-\fIxscreensaver\fP understands the following resources:
-.PP
+.B verbose\fP (class \fBBoolean\fP)
+Whether to print diagnostics. Default false.
.TP 8
-.B timeout \fR(class \fBTime\fP)
-Same as the \fI\-timeout\fP command-line option. Default 10 minutes.
+.B timestamp\fP (class \fBBoolean\fP)
+Whether to print the time of day along with any other diagnostic messages.
+Default false.
.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 lock \fR(class \fBBoolean\fP)
-Same as the \fI\-lock\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 lockTimeout \fR(class \fBTime\fP)
-Same as the \fI\-lock\-timeout\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 Netscape if it is already running,
+otherwise, will launch a new Netscape looking at the \fIhelpURL\fP.
.TP 8
-.B passwdTimeout \fR(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.) 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.
+.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 \fIxscreensaver\-demo\fP.
.TP 8
-.B verbose \fR(class \fBBoolean\fP)
-Same as the \fI\-verbose\fP command-line option.
+.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 xidle \fR(class \fBBoolean\fP)
-Same as the \fI\-xidle\fP command-line option.
+.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, that is, if the screen's default
-visual is a PseudoColor visual. Default true. A fade will also be done when
+visual is a PseudoColor visual. 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.
.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 3.)
+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 than the specified \fIfadeSeconds\fP if
your server isn't fast enough to keep up. Default 20.
.TP 8
-.B visualID \fR(class \fBVisualID\fP)
-Same as the \fI\-visual\fP command-line option. Default \fBdefault\fP.
-.TP 8
-.B installColormap \fR(class \fBBoolean\fP)
-Same as the \fI\-install\fP command-line option. Default true.
-.TP 8
-.B captureStderr \fR(class \fBBoolean\fP)
-Whether \fIxscreensaver\fP should redirect its standard-error stream to the
-window itself. Since its nature is to take over the screen, you would not
-normally see error messages generated by the screensaver or the programs it
+.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 instead of written to the controlling
-terminal of the screensaver driver process. Default true.
-.TP 8
-.B captureStdout \fR(class \fBBoolean\fP)
-Like \fBcaptureStderr\fP but for the standard-output stream. Default true.
+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 font \fR(class \fBFont\fP)
-The font used for the stdout/stderr text, if \fBcaptureStdout\fP or
-\fBcaptureStderr\fP are true. Default \fB*\-medium\-r\-*\-140\-*\-m\-*\fP
-(a 14 point fixed-width font.)
+.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 textForeground \fR(class \fBForeground\fP)
-The foreground color used for the stdout/stderr text, if \fBcaptureStdout\fP
-or \fBcaptureStderr\fP are true. Default: Yellow.
-.TP 8
-.B textBackground \fR(class \fBBackground\fP)
-The background color used for the stdout/stderr text, if \fBcaptureStdout\fP
-or \fBcaptureStderr\fP are true. Default: Black.
-.TP 8
-.B programs \fR(class \fBPrograms\fP)
+.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-syntax command per line.
-Each line must contain exactly one command -- no semicolons, no ampersands.
+Each line must contain exactly one command: no semicolons, no ampersands.
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
If the value of this resource is empty, then no programs will be run; the
screen will simply be made black.
-If the display has multiple screens, then a different program will be run
-for each screen.
+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\\
- xv -root -rmode 5 image.gif -quit \\n
+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. (Generally,
-this is accomplished by just including the \fI"vroot.h"\fP header file in
-the program's source.)
+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.)
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\\
+ 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 accomidated:
-
+a 24-bit visual, both can be accommodated:
.EX
- PseudoColor: cmap-program -root \\n\\
- TrueColor: 24bit-program -root \\n\\
+ PseudoColor: cmap-program -root \\n\\
+ TrueColor: 24bit-program -root \\n\\
.EE
.RE
.RS 8
-(This sort of thing used to be accomplished with the \fIcolorPrograms\fP
-and \fImonoPrograms\fP resources, but those resources have now been removed;
-a warning will be issued if they are used.)
+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
.PP
.PP
Normally you won't need to change the following resources:
+.PP
.TP 8
-.B bourneShell \fR(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,
-it must not be \fBcsh\fP.
+.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 windowCreationTimeout \fR(class \fBTime\fP)
+.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 pointerPollTime \fR(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 initialDelay \fR(class \fBTime\fP)
+.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 30 seconds.
-.TP 8
-.B overlayStderr \fR(class \fBBoolean\fP)
-If \fBcaptureStderr\fP or \fBcaptureStdout\fP are 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.)
-.SH "HOW IT WORKS"
+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...)
+.TP 8
+.B sgiSaverExtension\fP (class \fBBoolean\fP)
+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.
+
+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,
+it must not be \fBcsh\fP.
+.SH COMMAND-LINE OPTIONS
+.I xscreensaver
+also accepts the following command line options. Except for
+the \fI\-display\fP option, these command-line options are all
+simply shorthand for the X resources described in
+the \fIConfiguration\fP section, above.
+.TP 8
+.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; the \fIscreen\fP
+argument (the ``default'' screen) says which screen should be used for
+dialog boxes (the password window, \fIDemo Mode\fP, etc.)
+.TP 8
+.B \-timeout \fIminutes\fP
+Same as the \fItimeout\fP resource.
+.TP 8
+.B \-cycle \fIminutes\fP
+Same as the \fIcycle\fP resource.
+.TP 8
+.B \-lock\-mode
+Same as setting the \fIlock\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-lock\-mode
+Same as setting the \fIlock\fP resource to \fIfalse\fP.
+.TP 8
+.B \-lock\-timeout \fIminutes\fP
+Same as the \fIlockTimeout\fP resource.
+.TP 8
+.B \-visual \fIvisual\fP
+Same as the \fIvisualID\fP resource.
+.TP 8
+.B \-install
+Same as setting the \fIinstallColormap\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-install
+Same as setting the \fIinstallColormap\fP resource to \fIfalse\fP.
+.TP 8
+.B \-verbose
+Same as setting the \fIverbose\fP resource to \fItrue\fP.
+.TP 8
+.B \-silent
+Same as setting the \fIverbose\fP resource to \fIfalse\fP.
+.TP 8
+.B \-timestamp
+Same as setting the \fItimestamp\fP resource to \fItrue\fP.
+.TP 8
+.B \-capture\-stderr
+Same as setting the \fIcaptureStderr\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-capture\-stderr
+Same as setting the \fIcaptureStderr\fP resource to \fIfalse\fP.
+.TP 8
+.B \-splash
+Same as setting the \fIsplash\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-splash
+Same as setting the \fIsplash\fP resource to \fIfalse\fP.
+.TP 8
+.B \-nice \fIinteger\fP
+Same as the \fInice\fP resource.
+.TP 8
+.B \-sgi\-extension
+Same as setting the \fIsgiSaverExtension\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-sgi\-extension
+Same as setting the \fIsgiSaverExtension\fP resource to \fIfalse\fP.
+.TP 8
+.B \-mit\-extension
+Same as setting the \fImitSaverExtension\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-mit\-extension
+Same as setting the \fImitSaverExtension\fP resource to \fIfalse\fP.
+.TP 8
+.B \-xidle\-extension
+Same as setting the \fIxidleExtension\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-xidle\-extension
+Same as setting the \fIxidleExtension\fP resource to \fIfalse\fP.
+.TP 8
+.B \-proc\-interrupts
+Same as setting the \fIprocInterrupts\fP resource to \fItrue\fP.
+.TP 8
+.B \-no\-proc\-interrupts
+Same as setting the \fIprocInterrupts\fP resource to \fIfalse\fP.
+.TP 8
+.B \-xrm \fIresource-specification\fP
+As with all other Xt programs, you can specify X resources on the command-line
+using the \fI\-xrm\fP argument. Most of the interesting resources have
+command-line equivalents, however.
+.SH HOW IT WORKS
When it is time to activate the screensaver, a full-screen black window is
-created on each screen of the display. The window or windows 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.
+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
+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.
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, 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.
+
+If your X server supports power management, then
+.BR xset (1)
+will accept a \fBdpms\fP option. So, if you wanted \fIxscreensaver\fP
+to activate after 5 minutes, but you wanted your monitor to power down
+after one hour (3600 seconds) you would do this:
+.EX
+xset dpms 3600
+.EE
+See the man page for the
+.BR xset (1)
+program for details. (Note that power management requires both software
+support in the X server, and hardware support in the monitor itself.)
.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.
+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
+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
+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 \fIxdm-config\fP file. See the man page for
+in the \fI/usr/lib/X11/xdm/xdm-config\fP file. See the man page for
.BR xdm (1)
for more details.)
-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.
-
-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
+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.
-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; for example:
+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 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-command -exit ; xscreensaver
+xscreensaver &
.EE
-.SH DEMO MODE
-If \fIxscreensaver\fP receives the \fBDEMO\fP ClientMessage, which is done
-by running the \fBxscreensaver\-command\fP program with the \fB\-demo\fP
-option, the screensaver will black the screen and pop up a dialog box from
-which you can examine and experiment with the client programs.
-
-The dialog box contains a scrolling list, a text field, and a number of
-buttons.
-
-Double-clicking on one of the programs in the list will run it. Clicking
-the mouse again will bring the dialog box back.
-
-Single-clicking in the 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. (Note that these are
-one-time changes and won't be remembered; to make the changes permanent,
-you need to edit your X resource file.)
-
-The buttons are:
-.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 lock the screen. 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
-This causes the X resource database to be re-read, to pick up any changes
-you might have made. This works by causing the screensaver process to exit
-and then restart itself with the same command-line arguments. 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.
+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 ADDING TO MENUS
+The
+.BR xscreensaver-command (1)
+program is a perfect candidate for something to add to your window manager's
+popup menus. If you use
+.BR mwm (1),
+.BR 4Dwm (1),
+.BR twm (1),
+or (probably) any of \fItwm\fP's many descendants, you can do it like this:
+.RS 0
+.TP 3
+\fB1. Create ~/.mwmrc (or ~/.twmrc or ...)\fP
+If you don't have a \fI~/.mwmrc\fP file (or, on SGIs, a \fI~/.4Dwmrc\fP file;
+or, with twm, a \fI~/.twmrc\fP file) then create one by making a copy of
+the \fI/usr/lib/X11/system.mwmrc\fP
+file (or \fI/usr/lib/X11/twm/system.twmrc\fP, and so on.)
+.TP 3
+\fB2. Add a menu definition.\fP
+Something like this:
+.EX
+menu XScreenSaver
+{
+ "Blank Screen Now" !"sleep 3; xscreensaver-command -activate"
+ "Lock Screen Now" !"sleep 3; xscreensaver-command -lock"
+ "Screen Saver Demo" !"xscreensaver-demo"
+ "Screen Saver Preferences" !"xscreensaver-demo -prefs"
+ "Reinitialize Screen Saver" !"xscreensaver-command -restart"
+ "Kill Screen Saver" !"xscreensaver-command -exit"
+ "Launch Screen Saver" !"xscreensaver &"
+}
+.EE
+.TP 3
+\fB3. Add the menu\fP
+For
+.BR mwm (1)
+and
+.BR 4Dwm (1),
+find the section of the file that says \fIMenu DefaultRootMenu\fP.
+For
+.BR twm (1),
+it will probably be \fImenu "defops"\fP. If you add a line somewhere
+in that menu definition that reads
+.EX
+ "XScreenSaver" f.menu XScreenSaver
+.EE
+then this will add an XScreenSaver sub-menu to your default root-window
+popup menu. Alternately, you could just put the xscreensaver menu items
+directly into the root menu.
+.RE
+
+Other window managers are guaranteed to do things gratuitously differently.
.SH BUGS
-(This is not a bug, but) note that as of release 1.32, the \fBcolorPrograms\fP
-and \fBmonoPrograms\fP resources are no longer used: they have been
-supplanted by the extended syntax of the \fBprograms\fP resource (see above.)
+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
-Extensions
-If you are not making use of one of the server extensions (\fBXIDLE\fP,
-\fBSCREEN_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.
-.TP 8
-Machine Load
+.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.
+
+If anyone has suggestions on how xscreensaver could be made to work with
+.BR xdm (1)
+without first turning off \fI.Xauthority\fP-based access control, please
+let me know.
+.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. 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.
+
+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 suck a lot of
(or making liberal use of any \fI\-delay\fP options which the programs
may provide.)
+Note that the OpenGL-based graphics demos are real pigs on machines that
+don't have texture hardware.
+
Also, an active screensaver will cause your X server to be pretty much
permanently swapped in; but the same is true of any program that draws
periodically, like
or
.BR xload (1).
.TP 8
-Latency and Responsiveness
+.B Latency and Responsiveness
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
in code intended for use as a screensaver. This prevents too much graphics
activity from being buffered up.
.TP 8
-Locking and XDM
-Locking doesn't work if the screensaver is launched by \fIxdm\fP.
-The reason for this is that when it is launched by \fIxdm\fP, the
-screensaver process is owned by some standard user id (such as \fIroot\fP
-or \fIdaemon\fP) instead of the user who is logged in on the console:
-because the screensaver was started \fIbefore\fP anyone was logged in.
-In order for the screensaver to prompt for the password of the person
-who had logged in from \fIxdm\fP, it would need to know who that user was,
-and there is no reliable and safe way to figure that out. (And even if
-there was, there would be some other security issues here as well.)
-
-So if you want to use it as a locker, you must start it with your user id.
-If it has already been started by \fIxdm\fP, you can kill it with
-\fBxscreensaver-command -exit\fP, and then start it again as you.
-.TP 8
-Passwords
-If you get an error message 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. Care has
-been taken to make this a safe thing to do.
+.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.
-It also may mean that your system uses shadow passwords instead of the
-standard \fIgetpwent\fP interface; in that case, you may need to change
-some options in \fIconfig.h\fP and recompile.
+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. See the
+.BR XF86Config (5)
+manual for details.
-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. This turns out to be kind of hard to fix. (But remember,
-kids! Unix security doesn't do much more than keep honest people honest...)
-.TP 8
-TWM and Colormaps
-The \fBinstallColormap\fP option doesn't work very well with the
-.BR twm (1)
-window manager and its descendants.
+There is no way (as far as I can tell) to disable the VT-switching keystrokes.
-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.)
+Some Linux systems come with a VT_LOCKSWITCH ioctl, that one could
+theoretically use to prevent VT-switching while the screen is locked;
+but unfortunately, this ioctl can only be used by root, which means
+that xscreensaver can't use it (since xscreensaver disavows its privileges
+shortly after startup, for security reasons.)
-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...
-.TP 8
-XView Clients
+Any suggestions for other solutions to this problem are welcome.
+.TP 8
+.B XView Clients
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. If anyone has any insight on the
-cause of this problem, please let me know.
+cause of this problem, please let me know. (XView is an X11 toolkit that
+implements the (quite abominable) Sun OpenLook look-and-feel.)
.TP 8
-MIT Extension and Fading
+.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 may notice an unattractive flicker just before
+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 SGI Power Saver
+If you're running Irix 6.3, you might find that your monitor is powering down
+after an hour or two even if you've told it not to. This is fixed by SGI
+patches 2447 and 2537.
+.TP 8
+.B OpenGL Programs and Visuals
+Some of the graphics demos included with xscreensaver make use of the
+OpenGL (or MesaGL) 3D library, if it is available. It is possible (even
+likely) that \fIxscreensaver\fP's notion of the ``\fIbest\fP'' visual is
+not quite right for these GL programs.
+
+The odd thing about GL programs is that, unlike normal X11 programs, they
+tend to work best on a visual \fIhalf\fP as deep as the depth of the screen,
+since that way, they can do double-buffering. Try it and see, but you will
+probably find that, for these particular programs, you should specify the
+deepest visual that is half as deep as the screen. (See the discussion
+of the \fBprograms\fP resource in the \fIConfiguration\fP section, above.)
+
+For example, on a screen that supports both 24-bit TrueColor and 12-bit
+PseudoColor visuals, the 12-bit visual will probably work best (this is true
+of base-model SGI Indys: the 0x29 visual is the one you want.)
+
+Oddly, on SGI O2s (machines that have serious hardware support for GL), the
+12-bit PseudoColor visual looks awful (you get a black and white, flickery
+image.) On these machines, the visual you want turns out to be 0x31.
+However, 0x31 is but \fIone\fP of the \fIeight\fP 15-bit TrueColor visuals
+(yes, 8, and yes, 15) that the O2 X server provides. This is the only visual
+that works properly: as far as
+.BR xdpyinfo (1)
+is concerned, all of the 15-bit TrueColor visuals are identical, but some
+flicker like mad, and some have deeply weird artifacts (such as hidden
+surfaces that show through, as if depth worked backwards!)
+
+I suppose these other visuals must be tied to some arcane hardware feature...
+If anyone would care to explain it to me, that would be great.
+
+Your mileage, therefore, may vary dramatically.
.TP 8
-LessTif (Motif Clone)
-Rumor has it that demo mode is buggy if XScreenSaver was compiled with the
-GNU LessTif reimplementation of Motif. Since it works fine with OSF Motif
-on a variety of systems, I assume these problems are due to bugs in LessTif.
-Again, any insight would be appreciated.
+.B MesaGL and Voodoo Cards
+If you have a 3Dfx/Voodoo card, the default settings for xscreensaver will
+run the GL-based graphics demos in such a way that they will not take
+advantage of the 3D acceleration hardware. The solution is to change
+the \fBprograms\fP entries for the GL hacks from this:
+.EX
+ gears -root \\n\\
+.EE
+to this:
+.EX
+ MESA_GLX_FX=fullscreen gears \\n\\
+.EE
+That is, make sure that \fB$MESA_GLX_FX\fP is set to \fIfullscreen\fP, and
+don't tell the program to draw on the root window. This may seem strange,
+but the setup used by Mesa and these kinds of cards \fIis\fP strange!
+
+For those who don't know, these cards work by sitting between your normal
+video card and the monitor, and seizing control of the monitor when it's
+time to do 3D. But this means that accelerated 3D only happens in full-screen
+mode (you can't do it in a window, and you can't see the output of 3D and 2D
+programs simultaniously), and that 3D will probably drive your monitor at a
+lower resolution, as well. It's bizarre.
+
+If you find that GL programs only work properly when run as root, and not
+as normal users, then the problem is that your \fI/dev/3dfx\fP file is not
+configured properly. Check the Linux 3Dfx FAQ.
+.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...
.TP 8
-Red Hot Lava
+.B Red Hot Lava
There need to be a lot more graphics hacks. In particular, there should be
a simulation of a Lavalite (tm).
.SH ENVIRONMENT
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 and write 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 UPGRADES
The latest version can always be found at
-http://people.netscape.com/jwz/xscreensaver/
+http://www.jwz.org/xscreensaver/
.SH SEE ALSO
.BR X (1),
+.BR xscreensaver\-demo (1),
.BR xscreensaver\-command (1),
-.BR xlock (1),
-.BR xnlock (1),
-.BR xautolock (1),
.BR xdm (1),
+.BR xset (1),
+.BR Xsecurity (1),
+.BR xauth (1),
+.BR xhost (1).
+.BR ant (1),
+.BR atlantis (1),
.BR attraction (1),
+.BR blitspin (1),
+.BR bouboule (1),
+.BR braid (1),
+.BR bsod (1),
+.BR bubbles (1),
+.BR cage (1),
+.BR coral (1),
+.BR cynosure (1),
+.BR decayscreen (1),
+.BR deco (1),
+.BR drift (1),
+.BR epicycle (1),
+.BR fadeplot (1),
+.BR flag (1),
+.BR flame (1),
+.BR forest (1),
+.BR galaxy (1),
+.BR gears (1),
+.BR goop (1),
+.BR grav (1),
.BR greynetic (1),
+.BR halo (1),
.BR helix (1),
.BR hopalong (1),
+.BR hypercube (1),
+.BR ifs (1),
+.BR imsmap (1),
+.BR interference (1),
+.BR jigsaw (1),
+.BR julia (1),
+.BR kaleidescope (1),
+.BR laser (1),
+.BR lightning (1),
+.BR lisa (1),
+.BR lissie (1),
+.BR lmorph (1),
+.BR maze (1),
+.BR moebius (1),
+.BR moire (1),
+.BR moire2 (1),
+.BR morph3d (1),
+.BR mountain (1),
+.BR munch (1),
.BR noseguy (1),
+.BR pedal (1),
+.BR penrose (1),
+.BR pipes (1),
.BR pyro (1),
-.BR xroger (1),
.BR qix (1),
+.BR rd-bomb (1),
.BR rocks (1),
.BR rorschach (1),
-.BR blitspin (1),
-.BR imsmap (1),
-.BR slidescreen (1),
-.BR decayscreen (1),
-.BR maze (1),
-.BR hypercube (1),
-.BR halo (1),
-.BR flame (1),
-.BR pedal (1),
-.BR lmorph (1),
-.BR deco (1),
-.BR moire (1),
-.BR kaleidescope (1),
-.BR bubbles (1),
-.BR lightning (1),
-.BR strange (1),
-.BR fract (1),
-.BR spiral (1),
-.BR laser (1),
-.BR grav (1),
-.BR drift (1),
-.BR ifs (1),
-.BR julia (1),
-.BR penrose (1),
+.BR rotor (1),
+.BR rubik (1),
.BR sierpinski (1),
-.BR hopalong (1),
-.BR braid (1),
-.BR bouboule (1),
-.BR galaxy (1),
-.BR flag (1),
-.BR forest (1),
+.BR slidescreen (1),
+.BR slip (1),
.BR sphere (1),
-.BR lisa (1),
-.BR xdaliclock (1),
-.BR xbouncebits (1),
+.BR spiral (1),
+.BR sproingies (1),
+.BR stairs (1),
+.BR starfish (1),
+.BR strange (1),
+.BR superquadrics (1),
+.BR swirl (1),
+.BR triangle (1),
+.BR truchet (1),
+.BR vines (1),
+.BR worm (1),
+.BR xjack (1),
+.BR xlyap (1),
+.BR xroger (1),
+.BR bongo (1),
.BR ico (1),
+.BR xaos (1),
+.BR xbouncebits (1),
+.BR xcthugha (1),
+.BR xdaliclock (1),
+.BR xfishtank (1),
+.BR xmountains (1),
+.BR xsplinefun (1),
.BR xswarm (1),
-.BR xwave (1),
-.BR xv (1),
.BR xtacy (1),
-.BR bongo (1),
-.BR xfishtank (1)
+.BR xv (1),
+.BR xwave (1).
.SH COPYRIGHT
-Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997 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
+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@netscape.com>. Written in late 1991; first posted
+Jamie Zawinski <jwz@jwz.org>. Written in late 1991; first posted
to comp.sources.x on 13-Aug-1992.
Please let me know if you find any bugs or make any improvements.
-
+.SH ACKNOWLEDGEMENTS
Thanks to David Wojtowicz for implementing \fIlockTimeout\fP.
Thanks to Martin Kraemer for adding support for shadow passwords and
Thanks to Patrick Moreau for the VMS port.
+Thanks to Mark Bowyer for figuring out how to hook it up to CDE.
+
And huge thanks to Jon A. Christopher for implementing the Athena dialog
-support, so that locking and demo-mode work even if you don't have Motif.
+support, back in the days before Lesstif was a viable alternative to Motif.
projects / xscreensaver / blobdiff