-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"
-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.
-
-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$DISPLAY\fP in the environment that the child will recieve. (This is
-so that if you start \fIxscreensaver\fP with a \fI-display\fP argument, the
-programs which \fIxscreensaver\fP launches will draw on the same display;
-and so that the child will end up drawing on the appropriate screen of a
-multi-headed display.)
-
-When the screensaver turns off, or is killed, care is taken to restore
-the ``real'' virtual root window if there is one. Because of this, it is
-important that you not kill the screensaver process with \fIkill -9\fP if
-you are running a virtual-root window manager. If you kill it with \-9,
-you may need to restart your window manager to repair the damage. This
-isn't an issue if you aren't running a virtual-root window manager.
-
-For all the gory details, see the commentary at the top of xscreensaver.c.
-
-You can control a running screensaver process by using the
-.BR xscreensaver\-command (1)
-program (which see.)
-.SH USING XDM(1)
-You can run \fIxscreensaver\fP from your xdm session, so that the
-screensaver will run even when nobody is logged in on the console.
-Simply add \fB"xscreensaver &"\fP to your \fI/usr/lib/X11/xdm/Xsetup\fP
-file. Because \fIxdm\fP grabs the keyboard, keypresses will not make
-the screensaver deactivate, but any mouse activity will.
-
-Make sure you have \fB$PATH\fP set up correctly in the Xsetup script, or
-\fIxdm\fP won't be able to find \fIxscreensaver\fP, and/or \fIxscreensaver\fP
-won't be able to find its graphics hacks.
-
-(If your system does not seem to be executing the \fIXsetup\fP file, you
-may need to configure it to do so -- the traditional way to do this is
-to make that file the value of the \fIDisplayManager*setup\fP resource
-in the \fIxdm-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
-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, by using this pair of commands:
-
-.EX
- xscreensaver-command -exit ; xscreensaver
-.EE
-.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
-
- xscreensaver &
-
-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:
-
- ACTION XScreenSaver
- {
- LABEL XScreenSaver
- TYPE COMMAND
- EXEC_STRING xscreensaver-command -lock
- ICON Dtkey
- WINDOW_TYPE NO_STDIO
- }
-
-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:
-
- 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
- }
-
-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
-.PP
-.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 (which is
-described above, in the \fIresources\fP section.)
-.TP 8
-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.
-.TP 8
-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
-cycles. Care should be taken to slow down programs intended for use as
-screensavers by inserting strategic calls to
-.BR sleep (3)
-or
-.BR usleep (3)
-(or making liberal use of any \fI\-delay\fP options which the programs
-may provide.)
-
-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
-.BR xclock (1)
-or
-.BR xload (1).
-.TP 8
-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
-again (the
-.BR ico (1)
-demo has this problem if being run in full-speed mode). This can be
-alleviated by inserting strategic calls to
-.BR XSync (3)
-in code intended for use as a screensaver. This prevents too much graphics
-activity from being buffered up.
-.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.
-
-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 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. 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
-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 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...
-.TP 8
-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 section about the \fBprograms\fP
-resource. When programs only work with the default colormap, you need to
-use a syntax like this:
-
- default-n: xv -root image-1.gif -quit \\n\\
- default-n: xearth -nostars -wait 0 \\n\\
-
-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
-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. (XView is an X11 toolkit that
-implements the (quite abominable) Sun OpenLook look-and-feel.)
-.TP 8
-MIT Extension and Fading
-When using the \fBMIT-SCREEN-SAVER\fP extension in conjunction with
-the \fBfade\fP option, you may 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.
-.TP 8
-LessTif (Motif Clone)
-Demo mode is buggy if XScreenSaver was compiled against really old versions
-LessTif; if you use LessTif, use version 0.82 or newer.
-.TP 8
-Athena Widgets
-If you compiled against the Athena widget toolkit, the dialog boxes are
-pretty ugly, especially the password dialog. Use Motif! If you don't
-have OSF Motif, use GNU LessTif, it's free: http://www.lesstif.org/
-.TP 8
-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
-Red Hot Lava
-There need to be a lot more graphics hacks. In particular, there should be
-a simulation of a Lavalite (tm).