xscreensaver - extensible screen saver and screen locking framework
xscreensaver [-display host:display.screen] [-verbose] [-no-splash] [-no-capture-stderr] [-log filename]
xscreensaver(1) XScreenSaver manual xscreensaver(1)
NAME
xscreensaver - extensible screen saver and screen locking framework
SYNOPSIS
xscreensaver [-display host:display.screen] [-verbose] [-no-splash]
[-no-capture-stderr] [-log filename]
DESCRIPTION
The xscreensaver program waits until the keyboard and mouse have been
idle for a period, and then runs a graphics demo chosen at random. It
turns off as soon as there is any mouse or keyboard activity.
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.
It also provides configuration and control of your monitor's power-sav-
ing features.
GETTING STARTED
For the impatient, try this:
xscreensaver &
xscreensaver-demo
The xscreensaver-demo(1) program pops up a dialog box that lets you
configure the screen saver, and experiment with the various display
modes.
Note that xscreensaver has a client-server model: the xscreensaver pro-
gram is a daemon that runs in the background; it is controlled by the
foreground xscreensaver-demo(1) and xscreensaver-command(1) programs.
CONFIGURATION
The easiest way to configure xscreensaver is to simply run the xscreen-
saver-demo(1) program, and change the settings through the GUI. The
rest of this manual page describes lower level ways of changing set-
tings.
I'll repeat that because it's important:
The easy way to configure xscreensaver is to run the xscreensaver-
demo(1) program. You shouldn't need to know any of the stuff
described in this manual unless you are trying to do something
tricky, like customize xscreensaver for site-wide use or something.
Options to xscreensaver are stored in one of two places: in a .xscreen-
saver file in your home directory; or in the X resource database. If
the .xscreensaver file exists, it overrides any settings in the
resource database.
The syntax of the .xscreensaver file is similar to that of the .Xde-
faults file; for example, to set the timeout parameter in the .xscreen-
saver file, you would write the following:
timeout: 5
whereas, in the .Xdefaults file, you would write
xscreensaver.timeout: 5
If you change a setting in the .xscreensaver file while xscreensaver is
already running, it will notice this, and reload the file. (The file
will be reloaded the next time the screen saver needs to take some
action, such as blanking or unblanking the screen, or picking a new
graphics mode.)
If you change a setting in your X resource database, or if you want
xscreensaver to notice your changes immediately instead of the next
time it wakes up, then you will need to reload your .Xdefaults file,
and then tell the running xscreensaver process to restart itself, like
so:
xrdb < ~/.Xdefaults
xscreensaver-command -restart
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/share/X11/app-defaults/XScreenSaver, but differ-
ent systems might keep it in a different place.
When settings are changed in the Preferences dialog box (see above) the
current settings will be written to the .xscreensaver file. (The .Xde-
faults file and the app-defaults file will never be written by xscreen-
saver itself.)
COMMAND-LINE OPTIONS
xscreensaver also accepts a few command-line options, mostly for use
when debugging: for normal operation, you should configure things via
the ~/.xscreensaver file.
-display host:display.screen
The X display to use. For displays with multiple screens,
XScreenSaver will manage all screens on the display simultan-
iously.
-verbose
Same as setting the verbose resource to true: print diagnostics
on stderr and on the xscreensaver window.
-no-capture-stderr
Do not redirect the stdout and stderr streams to the xscreen-
saver window itself. If xscreensaver is crashing, you might
need to do this in order to see the error message.
-log filename
This is exactly the same as redirecting stdout and stderr to
the given file (for append). This is useful when reporting
bugs.
HOW IT WORKS
When it is time to activate the screensaver, a full-screen black window
is 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. The various graphics demos are, in fact, just
standalone programs that know how to draw on the provided window.
When the user becomes active again, the screensaver windows are
unmapped, and the running subprocesses are killed by sending them
SIGTERM. This is also how the subprocesses are killed when the screen-
saver 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 xscreen-
saver-command(1) program (which see).
POWER MANAGEMENT
Modern X servers contain support to power down the monitor after an
idle period. If the monitor has powered down, then xscreensaver will
notice this (after a few minutes), and will not waste CPU by drawing
graphics demos on a black screen. An attempt will also be made to
explicitly power the monitor back up as soon as user activity is
detected.
The ~/.xscreensaver file controls the configuration of your display's
power management settings: if you have used xset(1) to change your
power management settings, then xscreensaver will override those
changes with the values specified in ~/.xscreensaver (or with its
built-in defaults, if there is no ~/.xscreensaver file yet).
To change your power management settings, run xscreensaver-demo(1) and
change the various timeouts through the user interface. Alternatively,
you can edit the ~/.xscreensaver file directly.
If the power management section is grayed out in the xscreen-
saver-demo(1) window, then that means that your X server does not sup-
port 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 set-
tings 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.
USING GNOME
By default, GNOME 3 uses the gdm(8) screen shield to blank and lock the
screen, and does not run xscreensaver or offer any screensaver modes.
To run xscreensaver as part of your GNOME 3 session, symlink or copy
the file /usr/lib/xscreensaver/xscreensaver-autostart.desktop to your
~/.config/autostart/ directory.
To prevent GNOME screen shield from locking the display, run:
gsettings set org.gnome.desktop.screensaver lock-enabled false
To prevent gnome-shell from dimming and turning off the display, run:
gsettings set org.gnome.desktop.session idle-delay 0
BUGS
Bugs? There are no bugs. Ok, well, maybe. If you find one, please
let me know. https://www.jwz.org/xscreensaver/bugs.html explains how
to construct the most useful bug reports.
Locking and root logins
In order for it to be safe for xscreensaver to be launched by xdm,
certain precautions had to be taken, among them that xscreensaver
never runs as root. In particular, if it is launched as root (as
xdm is likely to do), xscreensaver will disavow its privileges, and
switch itself to a safe user id (such as nobody).
An implication of this is that if you log in as root on the con-
sole, xscreensaver will refuse to lock the screen (because it can't
tell the difference between root being logged in on the console,
and a normal user being logged in on the console but xscreensaver
having been launched by the xdm(1) Xsetup file).
The solution to this is simple: you shouldn't be logging in on the
console as root in the first place! (What, are you crazy or some-
thing?)
Proper Unix hygiene dictates that you should log in as yourself,
and su(1) to root as necessary. People who spend their day logged
in as root are just begging for disaster.
XAUTH and XDM
For xscreensaver to work when launched by xdm(1) or gdm(1), pro-
grams running on the local machine as user "nobody" 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 "Using GDM" section, above,
for more details.
Passwords
If you get an error message at startup like "couldn't get password
of user" then this probably means that you're on a system in which
the getpwent(3) library routine can only be effectively used by
root. If this is the case, then xscreensaver 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 getpwent(3) interface; in that case, you may need to
change some options with configure and recompile.
If you change your password after xscreensaver has been launched,
it will continue using your old password to unlock the screen until
xscreensaver is restarted. On some systems, it may accept both
your old and new passwords. So, after you change your password,
you'll have to do
xscreensaver-command -restart
to make xscreensaver notice.
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 /etc/pam.d/xscreen-
saver for you, and on Solaris, by telling you what lines to add to
the /etc/pam.conf file).
If the PAM configuration files do not know about xscreensaver, then
you might 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!
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 con-
sume many cycles. Care has been taken in all the modules shipped
with xscreensaver to sleep periodically, and not run full tilt, so
as not to cause appreciable load.
However, if you are running the OpenGL-based screen savers on a
machine that does not have a video card with 3D acceleration, they
will make your machine slow, despite nice(1).
Your options are: don't use the OpenGL display modes; or, collect
the spare change hidden under the cushions of your couch, and use
it to buy a video card manufactured after 1998. (It doesn't even
need to be fast 3D hardware: the problem will be fixed if there is
any 3D hardware at all.)
Magic Backdoor Keystrokes
The XFree86 X server and the Linux kernel both trap certain magic
keystrokes before X11 client programs ever see them. If you care
about keeping your screen locked, this is a big problem.
Ctrl+Alt+Backspace
This keystroke kills the X server, and on some systems, leaves
you at a text console. If the user launched X11 manually, that
text console will still be logged in. To disable this keystroke
globally and permanently, you need to set the DontZap flag in
your xorg.conf or XF86Config or XF86Config-4 file, depending
which is in use on your system. See XF86Config(5) for details.
Ctrl-Alt-F1, Ctrl-Alt-F2, etc.
These keystrokes will switch to a different virtual console,
while leaving the console that X11 is running on locked. If you
left a shell logged in on another virtual console, it is unpro-
tected. So don't leave yourself logged in on other consoles.
You can disable VT switching globally and permanently by setting
DontVTSwitch in your xorg.conf, but that might make your system
harder to use, since VT switching is an actual useful feature.
There is no way to disable VT switching only when the screen is
locked. It's all or nothing.
Ctrl-Alt-KP_Multiply
This keystroke kills any X11 app that holds a lock, so typing
this will kill xscreensaver and unlock the screen. This so-
called "feature" showed up in the X server in 2008, and as of
2011, some vendors are shipping it turned on by default. How
nice. You can disable it by turning off AllowClosedownGrabs in
xorg.conf.
Alt-SysRq-F
This is the Linux kernel "OOM-killer" keystroke. It shoots down
random long-running programs of its choosing, and so might might
target and kill xscreensaver, and there's no way for xscreen-
saver to protect itself from that. You can disable it globally
with:
echo 176 > /proc/sys/kernel/sysrq
There's little that I can do to make the screen locker be secure so
long as the kernel and X11 developers are actively working against
security like this. The strength of the lock on your front door
doesn't matter much so long as someone else in the house insists on
leaving a key under the welcome mat.
Dangerous Backdoor Server Extensions
Many distros enable by default several X11 server extensions that
can be used to bypass grabs, and thus snoop on you while you're
typing your password. These extensions are nominally for debugging
and automation, but they are also security-circumventing keystroke
loggers. If your server is configured to load the RECORD, XTRAP or
XTEST extensions, you absolutely should disable those, 100% of the
time. Look for them in xorg.conf or whatever it is called.
X RESOURCES
These are the X resources use by the xscreensaver program. You proba-
bly won't need to change these manually (that's what the xscreen-
saver-demo(1) program is for).
timeout (class Time)
The screensaver will activate (blank the screen) after the key-
board and mouse have been idle for this many minutes. Default
10 minutes.
cycle (class Time)
After the screensaver has been running for this many minutes,
the currently running graphics-hack sub-process will be killed
(with SIGTERM), and a new one started. If this is 0, then the
graphics hack will never be changed: only one demo will run
until the screensaver is deactivated by user activity. Default
10 minutes.
The running saver will be restarted every cycle minutes even
when mode is one, since some savers tend to converge on a
steady state.
lock (class Boolean)
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. (Note:
this doesn't work if the screensaver is launched by xdm(1)
because it can't know the user-id of the logged-in user. See
the "Using XDM(1)" section, below.
lockTimeout (class Time)
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 -timeout
is 10, then after 10 minutes, the screen would blank. If there
was user activity at 12 minutes, no password would be required
to un-blank the screen. But, if there was user activity at 15
minutes or later (that is, -lock-timeout minutes after activa-
tion) 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.
passwdTimeout (class Time)
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.
dpmsEnabled (class Boolean)
Whether power management is enabled.
dpmsStandby (class Time)
If power management is enabled, how long until the monitor goes
solid black.
dpmsSuspend (class Time)
If power management is enabled, how long until the monitor goes
into power-saving mode.
dpmsOff (class Time)
If power management is enabled, how long until the monitor pow-
ers down completely. Note that these settings will have no
effect unless both the X server and the display hardware sup-
port power management; not all do. See the Power Management
section, below, for more information.
dpmsQuickOff (class Boolean)
If mode is blank and this is true, then the screen will be pow-
ered down immediately upon blanking, regardless of other power-
management settings.
visualID (class VisualID)
This is an historical artifacts left over from when 8-bit dis-
plays were still common. You should probably ignore this.
Specify which X visual to use by default. (Note carefully that
this resource is called visualID, not merely visual; if you set
the visual resource instead, things will malfunction in obscure
ways for obscure reasons.)
Legal values for the VisualID resource are:
default Use the screen's default visual (the visual of the root
window). This is the default.
best Use the visual which supports the most colors. Note,
however, that the visual with the most colors might be
a TrueColor visual, which does not support colormap
animation. Some programs have more interesting behav-
ior when run on PseudoColor visuals than on TrueColor.
mono Use a monochrome visual, if there is one.
gray Use a grayscale or staticgray visual, if there is one
and it has more than one plane (that is, it's not mono-
chrome).
color Use the best of the color visuals, if there are any.
GL Use the visual that is best for OpenGL programs.
(OpenGL programs have somewhat different requirements
than other X programs.)
class where class is one of StaticGray, StaticColor, True-
Color, GrayScale, PseudoColor, or DirectColor. Selects
the deepest visual of the given class.
number where number (decimal or hex) is interpreted as a vis-
ual id number, as reported by the xdpyinfo(1) program;
in this way you can have finer control over exactly
which visual gets used, for example, to select a shal-
lower one than would otherwise have been chosen.
Note that this option specifies only the default visual that
will be used: the visual used may be overridden on a program-
by-program basis. See the description of the programs
resource, below.
installColormap (class Boolean)
On PseudoColor (8-bit) displays, install a private colormap
while the screensaver is active, so that the graphics hacks can
get as many colors as possible. This is the default. (This
only applies when the screen's default visual is being used,
since non-default visuals get their own colormaps automati-
cally.) This can also be overridden on a per-hack basis: see
the discussion of the default-n name in the section about the
programs resource.
This does nothing if you have a TrueColor (16-bit or deeper)
display. (Which, in this century, you do.)
verbose (class Boolean)
Whether to print diagnostics. Default false.
timestamp (class Boolean)
Whether to print the time of day along with any other diagnos-
tic messages. Default true.
splash (class Boolean)
Whether to display a splash screen at startup. Default true.
splashDuration (class Time)
How long the splash screen should remain visible; default 5
seconds.
helpURL (class URL)
The splash screen has a Help button on it. When you press it,
it will display the web page indicated here in your web
browser.
loadURL (class LoadURL)
This is the shell command used to load a URL into your web
browser. The default setting will load it into Mozilla/Net-
scape if it is already running, otherwise, will launch a new
browser looking at the helpURL.
demoCommand (class DemoCommand)
This is the shell command run when the Demo button on the
splash window is pressed. It defaults to xscreensaver-demo(1).
prefsCommand (class PrefsCommand)
This is the shell command run when the Prefs button on the
splash window is pressed. It defaults to xscreen-
saver-demo -prefs.
newLoginCommand (class NewLoginCommand)
If set, this is the shell command that is run when the "New
Login" button is pressed on the unlock dialog box, in order to
create a new desktop session without logging out the user who
has locked the screen. Typically this will be some variant of
gdmflexiserver(1), kdmctl(1), lxdm(1) or dm-tool(1).
nice (class Nice)
The sub-processes created by xscreensaver 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 unneces-
sarily. The default is 10. (Higher numbers mean lower prior-
ity; see nice(1) for details.)
fade (class Boolean)
If this is true, then when the screensaver activates, the cur-
rent contents of the screen will fade to black instead of sim-
ply winking out. This only works on certain systems. A fade
will also be done when switching graphics hacks (when the cycle
timer expires). Default: true.
unfade (class Boolean)
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 certain systems,
and if fade is true as well. Default false.
fadeSeconds (class Time)
If fade is true, this is how long the fade will be in seconds
(default 3 seconds).
fadeTicks (class Integer)
If fade 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 fadeSeconds if your server isn't fast enough to keep
up. Default 20.
captureStderr (class Boolean)
Whether xscreensaver should redirect its stdout and stderr
streams to the window itself. Since its nature is to take over
the screen, you would not normally see error messages generated
by xscreensaver or the sub-programs it runs; this resource will
cause the output of all relevant programs to be drawn on the
screensaver window itself, as well as being written to the con-
trolling terminal of the screensaver driver process. Default
true.
ignoreUninstalledPrograms (class Boolean)
There may be programs in the list that are not installed on the
system, yet are marked as "enabled". If this preference is
true, then such programs will simply be ignored. If false,
then a warning will be printed if an attempt is made to run the
nonexistent program. Also, the xscreensaver-demo(1) program
will suppress the non-existent programs from the list if this
is true. Default: false.
authWarningSlack (class Integer)
If all failed unlock attempts (incorrect password entered) were
made within this period of time, the usual dialog that warns
about such attempts after a successful login will be sup-
pressed. The assumption is that incorrect passwords entered
within a few seconds of a correct one are user error, rather
than hostile action. Default 20 seconds.
GetViewPortIsFullOfLies (class Boolean)
Set this to true if the xscreensaver window doesn't cover the
whole screen. This works around a longstanding XFree86 bug
#421. See the xscreensaver FAQ for details.
font (class Font)
The font used for the stdout/stderr text, if captureStderr is
true. Default *-medium-r-*-140-*-m-* (a 14 point fixed-width
font).
mode (class Mode)
Controls the behavior of xscreensaver. Legal values are:
random When blanking the screen, select a random display mode
from among those that are enabled and applicable. This
is the default.
random-same
Like random, but if there are multiple screens, each
screen will run the same random display mode, instead
of each screen running a different one.
one When blanking the screen, only ever use one particular
display mode (the one indicated by the selected set-
ting).
blank When blanking the screen, just go black: don't run any
graphics hacks.
off Don't ever blank the screen, and don't ever allow the
monitor to power down.
selected (class Integer)
When mode is set to one, this is the one, indicated by its
index in the programs list. You're crazy if you count them and
set this number by hand: let xscreensaver-demo(1) do it for
you!
programs (class Programs)
The graphics hacks which xscreensaver runs when the user is
idle. The value of this resource is a multi-line string, one
sh-syntax command per line. Each line must contain exactly one
command: no semicolons, no ampersands.
When the screensaver starts up, one of these is selected
(according to the mode setting), and run. After the cycle
period expires, it is killed, and another is selected and run.
If a line begins with a dash (-) then that particular program
is disabled: it won't be selected at random (though you can
still select it explicitly using the xscreensaver-demo(1) pro-
gram).
If all programs are disabled, then the screen will just be made
blank, as when mode is set to blank.
To disable a program, you must mark it as disabled with a dash
instead of removing it from the list. This is because the sys-
tem-wide (app-defaults) and per-user (.xscreensaver) settings
are merged together, and if a user just deletes 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 dis-
ables 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 simultaneously.)
Note that you must escape the newlines; here is an example of
how you might set this in your ~/.xscreensaver file:
programs: \
qix -root \n\
ico -r -faces -sleep 1 -obj ico \n\
xdaliclock -builtin2 -root \n\
xv -root -rmode 5 image.gif -quit \n
Make sure your $PATH environment variable is set up correctly
before xscreensaver is launched, or it won't be able to find
the programs listed in the programs 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 tvtwm(1). (Generally, this is accomplished by
just including the "vroot.h" header file in the program's
source.)
Visuals:
Because xscreensaver was created back when dinosaurs roamed the
earth, it still contains support for some things you've proba-
bly never seen, such as 1-bit monochrome monitors, grayscale
monitors, and monitors capable of displaying only 8-bit col-
ormapped images.
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:
mono: mono-program -root \n\
color: color-program -root \n\
More generally, you can specify the kind of visual that should
be used for the window on which the program will be drawing.
For example, if one program works best if it has a colormap,
but another works best if it has a 24-bit visual, both can be
accommodated:
PseudoColor: cmap-program -root \n\
TrueColor: 24bit-program -root \n\
In addition to the symbolic visual names described above (in
the discussion of the visualID resource) one other visual name
is supported in the programs list:
default-n
This is like default, but also requests the use of the
default colormap, instead of a private colormap. (That
is, it behaves as if the -no-install 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: xv(1), and xearth(1)) make
assumptions about the visual and colormap of the root win-
dow: assumptions which xscreensaver can violate.
If you specify a particular visual for a program, and that vis-
ual does not exist on the screen, then that program will not be
chosen to run. This means that on displays with multiple
screens of different depths, you can arrange for appropriate
hacks to be run on each. For example, if one screen is color
and the other is monochrome, hacks that look good in mono can
be run on one, and hacks that only look good in color will show
up on the other.
You shouldn't ever need to change the following resources:
pointerPollTime (class Time)
When server extensions are not in use, this controls how fre-
quently xscreensaver checks to see if the mouse position or
buttons have changed. Default 5 seconds.
pointerHysteresis (class Integer)
If the mouse moves less than this-many pixels in a second,
ignore it (do not consider that to be "activity"). This is so
that the screen doesn't un-blank (or fail to blank) just
because you bumped the desk. Default: 10 pixels.
windowCreationTimeout (class Time)
When server extensions are not in use, this controls the delay
between when windows are created and when xscreensaver selects
events on them. Default 30 seconds.
initialDelay (class Time)
When server extensions are not in use, xscreensaver will wait
this many seconds before selecting events on existing windows,
under the assumption that xscreensaver is started during your
login procedure, and the window state may be in flux. Default
0. (This used to default to 30, but that was back in the days
when slow machines and X terminals were more common...)
procInterrupts (class Boolean)
This resource controls whether the /proc/interrupts file should
be consulted to decide whether the user is idle. This is the
default if xscreensaver has been compiled on a system which
supports this mechanism (i.e., Linux systems).
The benefit to doing this is that xscreensaver 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, xscreen-
saver 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 really do 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 con-
sole manually.)
The default value for this resource is True, on systems where
it works.
overlayStderr (class Boolean)
If captureStderr 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 screen-
hack. Set this to False to disable that (though you shouldn't
need to).
overlayTextForeground (class Foreground)
The foreground color used for the stdout/stderr text, if cap-
tureStderr is true. Default: Yellow.
overlayTextBackground (class Background)
The background color used for the stdout/stderr text, if cap-
tureStderr is true. Default: Black.
bourneShell (class BourneShell)
The pathname of the shell that xscreensaver uses to start sub-
processes. This must be whatever your local variant of /bin/sh
is: in particular, it must not be csh.
ENVIRONMENT
DISPLAY to get the default host and display number, and to inform the
sub-programs of the screen on which to draw.
XSCREENSAVER_WINDOW
Passed to sub-programs to indicate the ID of the window on
which they should draw. This is necessary on Xinerama/RANDR
systems where multiple physical monitors share a single X11
"Screen".
PATH to find the sub-programs to run.
HOME for the directory in which to read the .xscreensaver file.
XENVIRONMENT
to get the name of a resource file that overrides the global
resources stored in the RESOURCE_MANAGER property.
UPGRADES
The latest version of xscreensaver, an online version of this manual,
and a FAQ can always be found at https://www.jwz.org/xscreensaver/
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+----------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+----------------------+
|Availability | desktop/xscreensaver |
+---------------+----------------------+
|Stability | Volatile |
+---------------+----------------------+
SEE ALSO
X(7), Xsecurity(7), xauth(1), xdm(1), gdm(8), gsettings(1), xhost(1),
xscreensaver-demo(1), xscreensaver-command(1), xscreen-
saver-gl-helper(1), xscreensaver-getimage(1), xscreensaver-text(1).
COPYRIGHT
Copyright (C) 1991-2018 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 war-
ranty.
AUTHOR
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.
And a huge thank you to the hundreds of people who have contributed, in
large ways and small, to the xscreensaver collection over the past two
decades!
NOTES
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://www.jwz.org/xscreensaver/xscreen-
saver-5.39.tar.gz
Further information about this software can be found on the open source
community website at https://www.jwz.org/xscreensaver/.
X Version 11 5.39 (12-Apr-2018) xscreensaver(1)