.if n .sp 1
.if t .sp .5
..
-.TH XScreenSaver 1 "24-Oct-98 (3.01)" "X Version 11"
+.TH XScreenSaver 1 "24-Feb-2002 (4.01)" "X Version 11"
.SH NAME
-xscreensaver - graphics hack and screen locker, launched when the user is idle
+xscreensaver - extensible screen saver framework, plus locking
.SH SYNOPSIS
.B xscreensaver
[\-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] \
-[\-xrm \fIresources\fP]
+[\-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)
-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.
+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 \fIxscreensaver\-demo\fP program should pop up a dialog box
-that lets you experiment with the xscreensaver settings and graphics
-modes.
+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 xscreensaver-command (1)
programs.
.SH CONFIGURATION
-Options to \fIxscreensaver\fP are specified in one of two places: in
+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.
+
+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 a \fI.xscreensaver\fP file exists, it overrides any settings
+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
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 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
.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.
.BR nice (1)
for details.)
.TP 8
+.B memoryLimit\fP (class \fBMemoryLimit\fP)
+The sub-processes created by \fIxscreensaver\fP will not be allowed to
+allocate more than this much memory (more accurately, this is the maximum
+size their address space may become.) If any sub-process tries to allocate
+more than this,
+.BR malloc (3)
+will fail, and the process will likely exit (or safely crash) rather than
+going forth and hogging memory.
+
+The assumption here is that if one of the screenhacks is trying to use
+a lot of memory, then something has gone wrong, and it's better to kill
+that program than to overload the machine.
+
+Default: 0, meaning "no limit." 30M is a good choice on most systems.
+(But beware that setting this to a small value can cause OpenGL programs
+to malfunction on certain systems.)
+.TP 8
.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. A fade will also be done when
-switching graphics hacks (when the \fIcycle\fP timer expires.)
-Default: true.
+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\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\fP (class \fBTime\fP)
If \fIfade\fP is true, this is how long the fade will be in
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-syntax command per line.
run. After the \fIcycle\fP period expires, it is killed, and another
is selected and run.
-If the value of this resource is empty, then no programs will be run; the
-screen will simply be made black.
+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 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\\
- 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
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
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\\
+ 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:
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
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.
+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 \-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.
+The X display to use. For displays with multiple screens, XScreenSaver
+will manage all screens on the display simultaniously.
.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 \-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.
+Same as setting the \fIverbose\fP resource to \fItrue\fP: print diagnostics
+on stderr and on the xscreensaver window.
+.TP 8
+.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 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.
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;
and so that the child will end up drawing on the appropriate screen of a
.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.
+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.
-If your X server supports power management, then
+As of version 3.28, the \fI~/.xscreensaver\fP file controls the
+configuration of your display's power management settings: if you have
+used
.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.)
+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)
To the file \fI/usr/lib/X11/xdm/Xsetup\fP, add the lines
.EX
+xhost +localhost
xscreensaver-command -exit
xscreensaver &
.EE
.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.)
+
+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 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;
.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
lock command.
.RE
.PP
+.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. Presumably, there is
+some way to turn off KDE's screensaver framework, and make it so that the
+usual
+.BR xscreensaver-demo (1)
+and
+.BR xscreensaver-command (1)
+mechanisms are used, in a similar way to how one can reconfigure CDE and
+VUE environments, above.
+
+But I don't know how. If you do, please let me know, and I'll document
+it here.
.SH ADDING TO MENUS
The
.BR xscreensaver-command (1)
directly into the root menu.
.RE
-Other window managers are guaranteed to do things gratuitously differently.
+For Fvwm2, the process is similar: first create a \fI~/.fvwm2rc\fP file
+if you don't already have one, by making a copy of
+the \fI/etc/X11/fvwm2/system.fvwm2rc\fP file. Then, add a menu definition
+to it:
+.EX
+AddToMenu XScreenSaver "XScreenSaver" Title
++ "Blank Screen Now" Exec xscreensaver-command -activate
++ "Lock Screen Now" Exec xscreensaver-command -lock
++ "Screen Saver Demo" Exec xscreensaver-command -demo
++ "Screen Saver Preferences" Exec xscreensaver-command -prefs
++ "Reinitialize Screen Saver" Exec xscreensaver-command -restart
++ "Kill Screen Saver" Exec xscreensaver-command -exit
++ "Launch Screen Saver" Exec xscreensaver
++ "Run Next Demo" Exec xscreensaver-command -next
++ "Run Previous Demo" Exec xscreensaver-command -prev
+
+# To put the XScreenSaver sub-menu at the end of the root menu:
+AddToMenu RootMenu "XScreenSaver" Popup XScreenSaver
+.EE
+The Enlightenment window manager keeps each of its menus in a separate
+file. So, you need to create a file
+named \fI~/.enlightenment/xscreensaver.menu\fP with the contents:
+.EX
+"XScreenSaver Commands"
+ "Blank Screen Now" NULL exec "xscreensaver-command -activate"
+ "Lock Screen Now" NULL exec "xscreensaver-command -lock"
+ "Screen Saver Demo" NULL exec "xscreensaver-command -demo"
+ "Screen Saver Prefs" NULL exec "xscreensaver-command -prefs"
+ "Reinitialize Saver" NULL exec "xscreensaver-command -restart"
+ "Kill Screen Saver" NULL exec "xscreensaver-command -exit"
+ "Launch Screen Saver" NULL exec "xscreensaver"
+.EE
+then add
+.EX
+ "XScreenSaver" NULL menu "xscreensaver.menu"
+.EE
+to \fI~/.enlightenment/file.menu\fP to put the XScreenSaver submenu on
+your left-button root-window menu.
+
+As you see, every window manager does this stuff gratuitously differently,
+just to make your life difficult. You are in a maze of twisty menu
+configuration languages, all alike.
.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
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 to
-a safe user id (such as \fInobody\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
let me know.
.TP 8
.B 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
+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. Care has
-been taken to make this a safe thing to do.
+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)
.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)
.BR mwm (1)
and
.BR olwm (1)
-window managers don't seem to have this problem. The race condition exists
-because X 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...
+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,
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\\
+ 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
or
.BR xload (1).
.TP 8
-.B Doom and Quake
-On some systems, Doom, Quake, and other games intercept the keyboard in
-ways that X programs can never detect. Therefore, when running these games,
-xscreensaver might think the console is idle, and activate. In the worst
-case, xscreensaver might blank the screen and mess up the game. Alternately,
-xscreensaver might activate on the X display while leaving the game visible,
-and merely cause the game to slow down.
-
-I don't know how to fix this, because I don't know how to detect the kind
-of keyboard activity that occurs during these games. Suggestions are welcome.
-.TP 8
.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
in code intended for use as a screensaver. This prevents too much graphics
activity from being buffered up.
.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. See the
+.BR XF86Config (5)
+manual for details.
+
+There is no way (as far as I can tell) to disable the VT-switching keystrokes.
+
+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.)
+
+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
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.
+If you're running Irix 6.5, this bug is back. I don't know a fix.
.TP 8
.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:
+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\\
+ gears -root \\n\\
.EE
to this:
.EX
- MESA_GLX_FX=fullscreen gears \\n\\
+ 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,
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 that 3D will probably drive your
-monitor at a lower resolution, as well. It's bizarre.
+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.
+
+This probably isn't ever necessary on more modern cards; I'm not sure.
+
+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,
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.
+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 UPGRADES
-The latest version can always be found at
-http://www.jwz.org/xscreensaver/
+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 xscreensaver\-demo (1),
.BR xscreensaver\-command (1),
+.BR xscreensaver\-gl\-helper (1),
.BR xdm (1),
.BR xset (1),
.BR Xsecurity (1),
.BR bouboule (1),
.BR braid (1),
.BR bsod (1),
+.BR bubble3d (1),
.BR bubbles (1),
.BR cage (1),
+.BR compass (1),
.BR coral (1),
+.BR critical (1),
+.BR crystal (1),
.BR cynosure (1),
.BR decayscreen (1),
.BR deco (1),
+.BR deluxe (1),
+.BR demon (1),
+.BR discrete (1),
+.BR distort (1),
.BR drift (1),
.BR epicycle (1),
.BR fadeplot (1),
.BR flag (1),
.BR flame (1),
+.BR flow (1),
.BR forest (1),
.BR galaxy (1),
.BR gears (1),
+.BR glplanet (1),
.BR goop (1),
.BR grav (1),
.BR greynetic (1),
.BR jigsaw (1),
.BR julia (1),
.BR kaleidescope (1),
+.BR kumppa (1),
+.BR lament (1),
.BR laser (1),
.BR lightning (1),
.BR lisa (1),
.BR lissie (1),
.BR lmorph (1),
+.BR loop (1),
.BR maze (1),
.BR moebius (1),
.BR moire (1),
.BR munch (1),
.BR noseguy (1),
.BR pedal (1),
+.BR penetrate (1),
.BR penrose (1),
+.BR petri (1),
+.BR phosphor (1),
.BR pipes (1),
+.BR pulsar (1),
.BR pyro (1),
.BR qix (1),
.BR rd-bomb (1),
.BR sierpinski (1),
.BR slidescreen (1),
.BR slip (1),
+.BR sonar (1),
.BR sphere (1),
.BR spiral (1),
+.BR spotlight (1),
.BR sproingies (1),
+.BR squiral (1),
.BR stairs (1),
.BR starfish (1),
.BR strange (1),
.BR superquadrics (1),
.BR swirl (1),
+.BR t3d (1),
.BR triangle (1),
.BR truchet (1),
.BR vines (1),
+.BR wander (1),
.BR worm (1),
+.BR xflame (1),
.BR xjack (1),
.BR xlyap (1),
-.BR xroger (1),
+.BR xmatrix (1),
.BR bongo (1),
.BR ico (1),
.BR xaos (1),
.BR xswarm (1),
.BR xtacy (1),
.BR xv (1),
+.BR chbg (1),
.BR xwave (1).
.SH COPYRIGHT
-Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
-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
+Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+2000, 2001, 2002 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@jwz.org>. Written in late 1991; first posted
-to comp.sources.x on 13-Aug-1992.
+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 the many people who have contributed graphics demos to the package.
-
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, back in the days before Lesstif was a viable alternative to Motif.
+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