.if n .sp 1
.if t .sp .5
..
-.TH XScreenSaver 1 "02-Oct-98 (2.31)" "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
[\-verbose] \
[\-silent] \
[\-timestamp] \
+[\-capture\-stderr] \
+[\-no\-capture\-stderr] \
[\-splash] \
[\-no\-splash] \
[\-nice \fIint\fP] \
[\-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
For the impatient, try this:
.EX
xscreensaver &
-xscreensaver-command -demo
+xscreensaver-demo
.EE
-After a few seconds, the screen should go black, and a dialog box should
-appear in the upper right corner. This is \fIDemo Mode\fP.
+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 xscreensaver process is a
+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)
-program.
-.SH DEMO MODE
-If \fIxscreensaver\fP receives the \fBDEMO\fP ClientMessage, which is done
-by running the
-.BR xscreensaver\-command (1)
-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. The dialog
-box will disappear, allowing the program access to the full screen. 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 Preferences
-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. (See the \fIConfiguration\fP section, below.)
-.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.
+programs.
.SH CONFIGURATION
-\fIxscreensaver\fP understands the following X resources. The best way
-to specify these parameters is to set them in your X resource file,
-which is usually called \fI~/.Xdefaults\fP. For example, to set the
-default value of the \fItimeout\fP resource, you would add the following
-line to your .Xdefaults file:
+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
-xscreensaver.timeout: 5
+timeout: 5
.EE
-To make the system notice this change, you might also need to run
-.BR xrdb (1):
+whereas, in the \fI.Xdefaults\fP file, you would write
.EX
-xrdb < ~/.Xdefaults
+xscreensaver.timeout: 5
.EE
-And if xscreensaver was already running, and you would like it to notice
-your changes, you'll also have to tell the running xscreensaver process
+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\fP (class \fBTime\fP)
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 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 prefsCommand\fP (class \fBPrefsCommand\fP)
+This is the shell command run when the \fIPrefs\fP button on the splash window
+is pressed. It defaults to \fIxscreensaver\-demo\ \-prefs\fP.
+.TP 8
.B nice\fP (class \fBNice\fP)
The sub-processes created by \fIxscreensaver\fP will be ``niced'' to this
level, so that they are given lower priority than other processes on the
.BR nice (1)
for details.)
.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 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
your server isn't fast enough to keep up. Default 20.
.TP 8
.B captureStderr\fP (class \fBBoolean\fP)
-Whether \fIxscreensaver\fP should redirect its standard-error stream to the
-window itself. Since its nature is to take over the screen, you would not
+Whether \fIxscreensaver\fP should redirect its stdout and stderr streams to
+the window itself. Since its nature is to take over the screen, you would not
normally see error messages generated by xscreensaver or the sub-programs it
runs; this resource will cause the output of all relevant programs to be
drawn on the screensaver window itself, as well as being written to the
controlling terminal of the screensaver driver process. Default true.
.TP 8
-.B captureStdout\fP (class \fBBoolean\fP)
-Like \fBcaptureStderr\fP but for the standard-output stream. Default true.
-.TP 8
.B font\fP (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.)
-.TP 8
-.B overlayTextForeground\fP (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 overlayTextBackground\fP (class \fBBackground\fP)
-The background color used for the stdout/stderr text, if \fBcaptureStdout\fP
-or \fBcaptureStderr\fP are true. Default: Black.
+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 programs\fP (class \fBPrograms\fP)
The graphics hacks which \fIxscreensaver\fP runs when the user is idle.
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:
Normally you won't need to change the following resources:
.PP
.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.
+.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\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\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 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
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 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.)
+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
.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\-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.
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$PATH\fP set up correctly in the Xsetup script, or
-\fIxdm\fP won't be able to find \fIxscreensaver\fP, and/or \fIxscreensaver\fP
-won't be able to find its graphics hacks.
+Make sure you have \fB$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
.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. Users who don't do
-this will get the system-wide defaults instead.
-
-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, by using this pair of commands:
+An unfortunate side effect of this (important) security precaution is that
+it may conflict with cookie-based authentication.
-.EX
-xscreensaver-command -exit
-xscreensaver
-.EE
If you get "connection refused" errors when running \fIxscreensaver\fP
from \fIxdm\fP, then this probably means that you have
.BR xauth (1)
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 \fIxdm\fP might not be
-possible, and users will have to launch it themselves instead of having it
-be launched by \fIxdm\fP before anyone logs in.
+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
.TP 3
\fB2: Edit sessionetc\fP
Edit the file \fI~/.dt/sessions/sessionetc\fP and add to it the line
-
.EX
xscreensaver &
.EE
\fB3: Create XScreenSaver.dt\fP
Create a file called \fI~/.dt/types/XScreenSaver.dt\fP with the following
contents:
-
.EX
ACTION XScreenSaver
{
\fB4: Create Lock.fp\fP
Create a file called \fI~/.dt/types/Lock.fp\fP with the following
contents:
-
.EX
CONTROL Lock
{
.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
{
"Blank Screen Now" !"sleep 3; xscreensaver-command -activate"
"Lock Screen Now" !"sleep 3; xscreensaver-command -lock"
- "Screen Saver Demo" !"xscreensaver-command -demo"
- "Screen Saver Preferences" !"xscreensaver-command -prefs"
+ "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 &"
"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 \fIxscreensaver-command\fP
-menu items directly into the root menu.
+popup menu. Alternately, you could just put the xscreensaver menu items
+directly into the root menu.
.RE
-Other window managers might (and probably do) do things differently.
+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 (which is
-described in the \fIConfiguration\fP section, above.)
-.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.
-.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
-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
-.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
-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.
+Bugs? There are no bugs. Ok, well, maybe. If you find one, please let
+me know. http://www.jwz.org/xscreensaver/bugs.html explains how to
+construct the most useful bug reports.
.TP 8
.B Locking and XDM
If xscreensaver has been launched from
-.BR xdm (1),
-you will need to cause the xscreensaver daemon to exit and restart in
-order to lock the screen.
+.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.)
-The reason for this is, if xscreensaver has been launched by
-.BR xdm (1),
-that means it was launched \fIbefore\fP you logged in: so it has no way of
-knowing who the logged-in user is, and therefore, whose password it should
-prompt for.
+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.
-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 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:
xscreensaver-command -exit
xscreensaver &
.EE
-See the ``\fIUsing XDM(1)\fP'' section, above, for more details.
+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
-An implication of the above is that if you log in as \fIroot\fP on the
-console, xscreensaver will refuse to lock the screen (because it can't tell
+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 run
-by
-.BR xdm (1)).
+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?) You
-should log in as you, and
+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
+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 \fB"xhost +localhost"\fP
-is required if xscreensaver is to be launched by
-.BR xdm (1).
-This is \fInot\fP required if \fIxscreensaver\fP is launched by the
-individual users: it is only necessary when it is launched by
-.BR xdm (1),
-before any user has logged in. See the ``\fIUsing XDM(1)\fP'' section,
+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
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 \fIgetpwent\fP interface; in that case, you may need to change
-some options with \fIconfigure\fP and recompile.
+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
.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
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
+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.)
+
+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
+.BR xclock (1)
+or
+.BR xload (1).
+.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
+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
+.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
implements the (quite abominable) Sun OpenLook look-and-feel.)
.TP 8
.B MIT Extension and Fading
+The \fBMIT-SCREEN-SAVER\fP extension is junk. Don't use it.
+
When using the \fBMIT-SCREEN-SAVER\fP extension in conjunction with
-the \fBfade\fP option, you 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
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
+extension in XFree86; it's dead simple, and works far better than the
overengineered and broken \fBMIT-SCREEN-SAVER\fP extension.
.TP 8
-.B Lesstif (Motif clone)
-\fIDemo Mode\fP is buggy if XScreenSaver was compiled against really old
-versions Lesstif; if you use Lesstif, make sure you use version 0.82 or newer.
-.TP 8
-.B 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
.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
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
+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
Your mileage, therefore, may vary dramatically.
.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:
+.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
.B Red Hot Lava
There need to be a lot more graphics hacks. In particular, there should be
a simulation of a Lavalite (tm).
.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.
http://www.jwz.org/xscreensaver/
.SH SEE ALSO
.BR X (1),
+.BR xscreensaver\-demo (1),
.BR xscreensaver\-command (1),
.BR xdm (1),
.BR xset (1),
.BR xv (1),
.BR xwave (1).
.SH COPYRIGHT
-Copyright \(co 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
+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
projects / xscreensaver / blobdiff