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diff --git a/driver/xscreensaver.man b/driver/xscreensaver.man index 0679ff4..9c3bdd0 100644 --- a/driver/xscreensaver.man +++ b/driver/xscreensaver.man @@ -1,208 +1,149 @@ -.de EX \"Begin example -.ne 5 -.if n .sp 1 -.if t .sp .5 -.nf -.in +.5i -.. -.de EE -.fi -.in -.5i -.if n .sp 1 -.if t .sp .5 -.. -.TH XScreenSaver 1 "6-Jun-2019 (5.43)" "X Version 11" +.TH XScreenSaver 1 "6-Jan-2021 (6.00)" "X Version 11" .SH NAME xscreensaver - extensible screen saver and screen locking framework .SH SYNOPSIS .B xscreensaver -[\-display \fIhost:display.screen\fP] \ -[\-verbose] \ -[\-no\-splash] \ -[\-no\-capture\-stderr] \ -[\-log \fIfilename\fP] +[\-\-display \fIhost:display.screen\fP] \ +[\-\-verbose] \ +[\-\-no\-splash] \ +[\-\-log \fIfilename\fP] .SH DESCRIPTION -The \fIxscreensaver\fP program waits until the keyboard and mouse have been -idle for a period, and then runs a graphics demo chosen at random. It -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. +XScreenSaver waits until the user is idle, and then runs graphics demos chosen +at random. It can also lock your screen, and provides configuration and +control of display power management. -It also provides configuration and control of your monitor's power-saving -features. +XScreenSaver is also available on macOS, iOS and Android. .SH GETTING STARTED -For the impatient, try this: -.EX -xscreensaver & -xscreensaver-demo -.EE -The -.BR xscreensaver-demo (1) -program pops up a dialog box that lets you configure the screen saver, -and experiment with the various display modes. - -.B Note that xscreensaver has a client-server model: -the \fIxscreensaver\fP program is a daemon that runs in the background; -it is controlled by the foreground -.BR xscreensaver-demo (1) -and -.BR xscreensaver-command (1) -programs. -.SH CONFIGURATION -The easiest way to configure \fIxscreensaver\fP is to simply run the -.BR xscreensaver-demo (1) -program, and change the settings through the GUI. The rest of this -manual page describes lower level ways of changing settings. - -I'll repeat that because it's important: +XScreenSaver is a daemon that runs in the background. You configure it +with the +.BR xscreensaver\-settings (1) +program. +.nf +.sp + xscreensaver & + xscreensaver-settings +.sp +.fi -.RS 4 -The easy way to configure xscreensaver is to run the -.BR xscreensaver-demo (1) -program. You shouldn't need to know any of the stuff described -in \fIthis\fP manual unless you are trying to do something tricky, -like customize xscreensaver for site-wide use or something. -.RE +.SH HOW IT WORKS +When it is time to activate the screensaver, a full-screen black window is +created that covers each monitor. A sub-process is launched for each one +running a graphics demo, pointed at the appropriate window. Because of this, +any program which can draw on a provided window can be used as a screensaver. +The various graphics demos are, in fact, just standalone programs that do +that. -Options to \fIxscreensaver\fP are stored in one of two places: in -a \fI.xscreensaver\fP file in your home directory; or in the X resource -database. If the \fI.xscreensaver\fP file exists, it overrides any settings -in the resource database. +When the user becomes active again, the screensaver windows are unmapped, and +the running subprocesses are killed. -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 parameter -in the \fI.xscreensaver\fP file, you would write the following: -.EX -timeout: 5 -.EE -whereas, in the \fI.Xdefaults\fP file, you would write -.EX -xscreensaver.timeout: 5 -.EE -If you change a setting in the \fI.xscreensaver\fP file while xscreensaver -is already running, it will notice this, and reload the file. (The file will -be reloaded the next time the screen saver needs to take some action, such as -blanking or unblanking the screen, or picking a new graphics mode.) +The display modes are run at a low process priority, and spend most of their +time sleeping/idle by default, so they should not consume significant system +resources. -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 \fI.Xdefaults\fP file, -and then tell the running xscreensaver process to restart itself, like so: -.EX -xrdb < ~/.Xdefaults -xscreensaver-command -restart -.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.) .SH COMMAND-LINE OPTIONS -.I xscreensaver -also accepts a few command-line options, mostly for use when debugging: -for normal operation, you should configure things via the \fI~/.xscreensaver\fP -file. .TP 8 -.B \-display \fIhost:display.screen\fP +.B \-\-display \fIhost:display.screen\fP The X display to use. For displays with multiple screens, XScreenSaver -will manage all screens on the display simultaniously. +will manage all screens on the display simultaneously. .TP 8 -.B \-verbose -Same as setting the \fIverbose\fP resource to \fItrue\fP: print diagnostics -on stderr and on the xscreensaver window. +.B \-\-verbose +Print diagnostics to stderr. .TP 8 -.B \-no-capture-stderr -Do not redirect the stdout and stderr streams to the xscreensaver window -itself. If xscreensaver is crashing, you might need to do this in order -to see the error message. +.B \-\-log \fIfilename\fP +Append all diagnostic output to the given file. This also +implies \fI\-\-verbose\fP. Use this when reporting bugs. .TP 8 -.B \-log \fIfilename\fP -This is exactly the same as redirecting stdout and stderr to the given -file (for append). This is useful when reporting bugs. -.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. 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 \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. +.B \-\-no\-splash +Don't display the splash screen at startup. -You can control a running screensaver process by using the -.BR xscreensaver\-command (1) -program (which see). .SH POWER MANAGEMENT -Modern X servers contain support to power down the monitor after an idle -period. If the monitor has powered down, then \fIxscreensaver\fP will -notice this (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 \fI~/.xscreensaver\fP file controls the configuration of your -display's power management settings: if you have used -.BR xset (1) -to change your power management settings, then xscreensaver will -override those changes with the values specified -in \fI~/.xscreensaver\fP (or with its built-in defaults, if there -is no \fI~/.xscreensaver\fP file yet). - -To change your power management settings, run -.BR xscreensaver\-demo (1) -and change the various timeouts through the user interface. -Alternatively, you can edit the \fI~/.xscreensaver\fP file directly. +The +.BR xscreensaver\-settings (1) +program is where you configure if and when your monitor should power off. +It saves the settings in your \fI~/.xscreensaver\fP file. If the power management section is grayed out in the -.BR xscreensaver\-demo (1) +.BR xscreensaver\-settings (1) window, then that means that your X server does not support the XDPMS extension, and so control over the monitor's power state is not available. -If you're using a laptop, don't be surprised if changing the DPMS -settings has no effect: many laptops have monitor power-saving behavior -built in at a very low level that is invisible to Unix and X. On such -systems, you can typically adjust the power-saving delays only by -changing settings in the BIOS in some hardware-specific way. +When the monitor is powered down, the display hacks are stopped +(though it may take a minute or two for XScreenSaver to notice). -If DPMS seems not to be working with XFree86, make sure the "DPMS" -option is set in your \fI/etc/X11/XF86Config\fP file. See the -.BR XF86Config (5) -manual for details. -.SH USING GNOME OR UNITY -For the better part of a decade, GNOME shipped xscreensaver as-is, -and everything just worked out of the box. In 2005, however, they -decided to re-invent the wheel and ship their own replacement for -the \fIxscreensaver\fP daemon called "\fIgnome-screensaver\fP", -rather than improving xscreensaver and contributing their changes -back. As a result, the "\fIgnome-screensaver\fP" program is insecure, -bug-ridden, and missing many features of xscreensaver. You shouldn't -use it. - -To replace gnome-screensaver with xscreensaver: +Note: if you use +.BR xset (1) +to change the power management settings, XScreenSaver will override those +changes. Whatever is in the \fI~/.xscreensaver\fP file takes precedence. + +.SH LAPTOP LIDS +If your system has +.BR systemd (1) +221 or newer, or +.BR elogind (8), +then closing the lid of your laptop will cause the screen to lock immediately. + +If not, then the screen might not lock until a few seconds \fIafter\fP you +re-open the lid. Which is less than ideal. So if you don't +use \fIsystemd\fP, you might want to get in the habit of +doing \fIxscreensaver-command --lock\fP before closing the lid. + +.SH PLAYING VIDEOS +Likewise, if you have +.BR systemd (1) +221 or newer, or +.BR elogind (8), +then all of the popular video players and web browsers will +prevent XScreenSaver from blanking the screen while video is playing. + +Both of these features require that +.BR xscreensaver\-systemd (MANSUFFIX) +be able connect to the systemd bus. Parts of KDE and GNOME may need to be +disabled first for that to work; see below. + +.SH INSTALLATION +Each desktop environment has its own system for launching long-running +daemons like XScreenSaver, and since many of them come bundled with +their own (buggy, insecure, inferior) screen-locking frameworks, it is +also necessary to disable those other frameworks before XScreenSaver +can work. + +.SS INSTALLING XSCREENSAVER ON GNOME OR UNITY +For many years, GNOME shipped XScreenSaver as-is, and everything just worked. +In 2005, however, they decided to needlessly re-invent the wheel and ship +their own replacement for the \fIxscreensaver\fP daemon called +.BR gnome-screensaver (1) +rather than improving XScreenSaver and contributing their changes back. As a +result, the \fIgnome-screensaver\fP program is insecure, bug-ridden, and +missing many features of XScreenSaver. In fact, in 2011 it lost the ability +to run display modes at all. + +In 2012 some distros forked and renamed it as both +.BR mate-screensaver (1) +and +.BR cinnamon-screensaver (1), +which seem to be basically the same. + +To replace gnome-screensaver with XScreenSaver: .RS 4 .TP 3 -\fB1: Fully uninstall the gnome-screensaver package.\fP -.EX -sudo apt-get remove gnome-screensaver -.EE -or possibly -.EX -sudo dpkg -P gnome-screensaver -.EE +\fB1: Fully uninstall the other screen saver packages:\fP +.nf +.sp + sudo apt-get remove gnome-screensaver + sudo apt-get remove mate-screensaver + sudo apt-get remove cinnamon-screensaver +or + sudo rpm -e gnome-screensaver + sudo rpm -e mate-screensaver + sudo rpm -e cinnamon-screensaver +.sp +.fi +Be careful that it doesn't try to uninstall all of GNOME. + .TP 3 -\fB2: Launch xscreensaver at login.\fP +\fB2: Launch XScreenSaver at login.\fP + Select "\fIStartup Applications\fP" from the menu (or manually launch "\fIgnome-session-properties\fP") and add "\fIxscreensaver\fP". @@ -210,27 +151,49 @@ Do this as your normal user account, not as root. (This should go without saying, because you should never, ever, ever be logged in to the graphical desktop as user "root".) .TP 3 -\fB3: Make GNOME's "Lock Screen" use xscreensaver.\fP -.EX -sudo ln -sf /usr/bin/xscreensaver-command \\ +\fB3: Make GNOME's "Lock Screen" use XScreenSaver.\fP +.nf +.sp + sudo ln -sf /usr/bin/xscreensaver-command \\ /usr/bin/gnome-screensaver-command -.EE +.sp +.fi That doesn't work under Unity, though. Apparently it has its own built-in screen locker which is not gnome-screensaver, and cannot be removed, and yet still manages to be bug-addled and insecure. Keep reinventing that wheel, guys! (If you have figured out how to -replace Unity's locking "feature" with xscreensaver, let me know.) +replace Unity's locking "feature" with XScreenSaver, let me know.) + .TP 3 \fB4: Turn off Unity's built-in blanking.\fP + Open "\fISystem Settings / Brightness & Lock\fP"; .br Un-check "\fIStart Automatically\fP"; .br Set \fI"Turn screen off when inactive for"\fP to \fI"Never".\fP -.SH USING KDE +.br +Or possibly that has been randomly renamed again: +.br +Set "\fISettings / Power / Power Settings\fP" to \fI"Never".\fP +.TP 3 +\fB5: Stop GNOME from blocking XScreenSaver's "systemd" integration:\fP +.nf +.sp + sudo systemctl \-\-user mask gsd\-screensaver\-proxy.service +.sp +.fi +Without the above, video players will not be able to tell XScreenSaver +not to blank the screen while videos are playing, and the screen will not +auto-lock when you close your laptop's lid. + +After running that command, reboot. Yes, you have to reboot; it won't let +you simply stop the service. Logging out won't do it either. + +.SS INSTALLING XSCREENSAVER ON KDE Like GNOME, KDE also decided to invent their own screen saver framework -from scratch instead of simply using xscreensaver. To replace the KDE -screen saver with xscreensaver, do the following: +from scratch instead of simply using XScreenSaver. To replace the KDE +screen saver with XScreenSaver, do the following: .RS 4 .TP 3 \fB1: Turn off KDE's screen saver.\fP @@ -257,19 +220,21 @@ add "\fI/usr/bin/xscreensaver\fP". If you are lucky, that will create a \fI"xscreensaver.desktop"\fP file for you in \fI~/.config/autostart/\fP or \fI~/.kde/Autostart/\fP. .TP 3 -\fB3: Make xscreensaver be an Autostart program.\fP +\fB3: Make XScreenSaver be an Autostart program.\fP If it does not already exist, create a file in your autostart directory called \fIxscreensaver.desktop\fP that contains the following six lines: -.EX -[Desktop Entry] -Exec=xscreensaver -Name=XScreenSaver -Type=Application -StartupNotify=false -X-KDE-StartupNotify=false -.EE +.nf +.sp + [Desktop Entry] + Exec=xscreensaver + Name=XScreenSaver + Type=Application + StartupNotify=false + X-KDE-StartupNotify=false +.sp +.fi .TP 3 -\fB4: Make the various "lock session" buttons call xscreensaver.\fP +\fB4: Make the various "lock session" buttons call XScreenSaver.\fP The file you want to replace next has moved around over the years. It might be called \fI/usr/libexec/kde4/kscreenlocker\fP, or it might be called "\fIkdesktop_lock\fP" or "\fIkrunner_lock\fP" @@ -278,52 +243,96 @@ it might be in \fI/usr/lib/kde4/libexec/\fP or in \fI/usr/kde/3.5/bin/\fP or even in \fI/usr/bin/\fP, depending on the distro and phase of the moon. Replace the contents of that file with these two lines: -.EX -#!/bin/sh -xscreensaver-command -lock -.EE +.nf +.sp + #!/bin/sh + xscreensaver-command \-\-lock +.sp +.fi Make sure the file is executable (chmod a+x). -.RE -.PP -Now use xscreensaver normally, controlling it via the usual -.BR xscreensaver-demo (1) -and -.BR xscreensaver-command (1) -mechanisms. -.SH USING SYSTEMD +.TP 3 +\fB5: Stop KDE from blocking XScreenSaver's "systemd" integration:\fP +You must arrange for KDE's +.BR ksmserver (1) +daemon to be launched with the command line switch \fI\-\-no\-lockscreen\fP. + +One way to accomplish that is to edit the +.BR startkde (1) +script in \fI/usr/bin/\fP by hand, then log out and log back in. Another +way would be to wrap the \fIksmserver\fP program: +.nf +.sp + mv /usr/bin/ksmserver /usr/bin/ksmserver-orig +.sp +.fi +and replace \fI/usr/bin/ksmserver\fP with: +.nf +.sp + #!/bin/sh + ksmserver-orig \-\-no\-lockscreen +.sp +.fi +Either change will, of course, get blown away the next time your system +upgrades KDE. + +Instead of being in \fI/usr/bin/\fP, the \fIksmserver\fP program might be +in \fI/usr/lib/\fP or \fIusr/lib*/libexec/\fP or \fIusr/lib/*/libexec/\fP +or somewhere else, depending on your distro. + +But without this, video players will not be able to tell XScreenSaver not to +blank the screen while videos are playing, and the screen will not auto-lock +when you close your laptop's lid. + +It seems that KDE 5.17 replaced \fIstartkde\fP with \fIstartplasma-x11\fP, +and I don't know how to change how \fIthat\fP launches \fIksmserver\fP. +Let me know if you figure it out. + +.SS LAUNCHING XSCREENSAVER FROM SYSTEMD If the above didn't do it, and your system has .BR systemd (1), -then give this a try: +maybe this is how it works: +.RS 4 .TP 3 \fB1: Create a service.\fP Create the file \fI~/.config/systemd/user/xscreensaver.service\fP containing: -.EX -[Unit] -Description=XScreenSaver -[Service] -ExecStart=/usr/bin/xscreensaver -[Install] -WantedBy=default.target -.EE +.nf +.sp + [Unit] + Description=XScreenSaver + [Service] + ExecStart=/usr/bin/xscreensaver + Restart=on-failure + [Install] + WantedBy=default.target +.sp +.fi .TP 3 \fB2. Enable it.\fP -.EX -systemctl --user enable xscreensaver -.EE +.nf +.sp + systemctl \-\-user enable xscreensaver +.sp +.fi +.RE Then restart X11. -.SH USING UPSTART -If it's still not working, but on your distro, that newfangled -.BR systemd (1) -nonsense has already fallen out of favor? Then maybe this will work: -launch the \fI"Startup Applications"\fP applet, click \fI"Add"\fP, -enter these lines, then restart X11: -.EX -Name: XScreenSaver -Command: xscreensaver -Comment: xscreensaver -.EE -.SH USING GDM + +.SS LAUNCHING XSCREENAVER FROM UPSTART +If your system has +.BR upstart (7) +instead of +.BR systemd (1), +maybe this will work: launch the \fI"Startup Applications"\fP applet, +click \fI"Add"\fP, enter these lines, then restart X11: +.nf +.sp + Name: XScreenSaver + Command: xscreensaver + Comment: XScreenSaver +.sp +.fi + +.SS LAUNCHING XSCREENSAVER FROM GDM You can run \fIxscreensaver\fP from your .BR gdm (1) session, so that the screensaver will run even when nobody is logged @@ -334,20 +343,22 @@ On the \fIGeneral\fP page set the \fILocal Greeter\fP to \fIStandard Greeter\fP. On the \fIBackground\fP page, type the -command \fB"xscreensaver -nosplash"\fP into the \fIBackground Program\fP -field. That will cause gdm to run xscreensaver while nobody is logged +command \fB"xscreensaver \-\-nosplash"\fP into the \fIBackground Program\fP +field. That will cause gdm to run XScreenSaver while nobody is logged in, and kill it as soon as someone does log in. (The user will then -be responsible for starting xscreensaver on their own, if they want.) +be responsible for starting XScreenSaver on their own, if they want.) If that doesn't work, you can edit the config file directly. Edit \fI/etc/X11/gdm/gdm.conf\fP to include: -.EX -Greeter=/usr/bin/gdmlogin -BackgroundProgram=xscreensaver -nosplash -RunBackgroundProgramAlways=true -.EE +.nf +.sp + Greeter=/usr/bin/gdmlogin + BackgroundProgram=xscreensaver \-\-nosplash + RunBackgroundProgramAlways=true +.sp +.fi In this situation, the \fIxscreensaver\fP process will probably be running -as user \fIgdm\fP instead of \fIroot\fP. You can configure the settings +as user \fIgdm\fP instead of as \fIroot\fP. You can configure the settings for this nobody-logged-in state (timeouts, DPMS, etc.) by editing the \fI~gdm/.xscreensaver\fP file. @@ -369,127 +380,26 @@ X server's access control mechanisms, see the man pages for .BR xauth (1), and .BR xhost (1). -.SH LAPTOP LIDS -If you are running a system with -.BR systemd (1) -221 or newer, and if xscreensaver was compiled with \fIlibsystemd\fP -support, then closing the lid of your laptop will cause the screen to -lock immediately. -If not, then the screen might not lock until a few seconds \fIafter\fP you -re-open the lid. Which is less than ideal. So if you don't -use \fIsystemd\fP, you might want to get in the habit of -doing \fIxscreensaver-command -lock\fP before closing the lid. -.SH 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. -.PP -.TP 4 -.B Locking and root logins -In order for it to be safe for xscreensaver to be launched by \fIxdm\fP, -certain precautions had to be taken, among them that xscreensaver never -runs as \fIroot\fP. In particular, if it is launched as root (as \fIxdm\fP -is likely to do), xscreensaver will disavow its privileges, and switch -itself to a safe user id (such as \fInobody\fP). +.SS LAPTOP LIDS WITHOUT SYSTEMD +BSD systems or other systems without +.BR systemd (1) +or +.BR elogind (8) +might have luck by adding \fIxscreensaver\-command \-\-suspend\fP to +some appropriate spot in \fI/etc/acpi/events/anything\fP or in +\fI/etc/acpi/handler.sh\fP, if those files exist. -An implication of this is that if you log in as \fIroot\fP on the console, -xscreensaver will refuse to lock the screen (because it can't tell -the difference between \fIroot\fP being logged in on the console, and a -normal user being logged in on the console but xscreensaver having been -launched by the -.BR xdm (1) -.I Xsetup -file). +.SH SECURITY CONCERNS +XScreenSaver has a decades-long track record of securely locking your screen. +However, there are many things that can go wrong. X11 is a very old system, +and has a number of design flaws that make it susceptible to foot-shooting. -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?) +.SS MAGIC BACKDOOR KEYSTROKES +The XFree86 and Xorg X servers, as well as 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. -Proper Unix hygiene dictates that you should log in as yourself, and -.BR su (1) -to \fIroot\fP as necessary. People who spend their day logged in -as \fIroot\fP are just begging for disaster. -.TP 4 -.B XAUTH and XDM -For xscreensaver to work when launched by -.BR xdm (1) -or -.BR gdm (1), -programs running on the local machine as user \fI"nobody"\fP must be -able to connect to the X server. This means that if you want to run -xscreensaver on the console while nobody is logged in, you may need -to disable cookie-based access control (and allow all users who can log -in to the local machine to connect to the display). - -You should be sure that this is an acceptable thing to do in your -environment before doing it. See the "\fIUsing GDM\fP" section, -above, for more details. -.TP 4 -.B Passwords -If you get an error message at startup like "couldn't get password -of \fIuser\fP" then this probably means that you're on a system in which -the -.BR getpwent (3) -library routine can only be effectively used by root. If this is the case, -then \fIxscreensaver\fP must be installed as setuid to root in order for -locking to work. Care has been taken to make this a safe thing to do. - -It also may mean that your system uses shadow passwords instead of the standard -.BR getpwent (3) -interface; in that case, you may need to change some options -with \fIconfigure\fP and recompile. - -If you change your password after xscreensaver has been launched, it will -continue using your old password to unlock the screen until xscreensaver -is restarted. On some systems, it may accept \fIboth\fP your old and new -passwords. So, after you change your password, you'll have to do -.EX -xscreensaver-command -restart -.EE -to make \fIxscreensaver\fP notice. -.TP 4 -.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 4 -.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 consume 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 \fIwill\fP -make your machine slow, despite -.BR 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 -\fIfast\fP 3D hardware: the problem will be fixed if there is any -3D hardware \fIat all.\fP) -.TP 4 -.B 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. -.RS 4 .TP 3 .B Ctrl+Alt+Backspace This keystroke kills the X server, and on some systems, leaves you at @@ -500,6 +410,7 @@ permanently, you need to set the \fBDontZap\fP flag in your depending which is in use on your system. See .BR XF86Config (5) for details. + .TP 3 .B Ctrl-Alt-F1, Ctrl-Alt-F2, etc. These keystrokes will switch to a different virtual console, while @@ -512,48 +423,147 @@ 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. + .TP 3 .B 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 -\fBAllowClosedownGrabs\fP in \fIxorg.conf\fP. +will kill XScreenSaver and unlock the screen. You can disable it by +turning off \fBAllowClosedownGrabs\fP in \fIxorg.conf\fP. + .TP 3 .B 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 xscreensaver to -protect itself from that. You can disable it globally with: -.EX -echo 176 > /proc/sys/kernel/sysrq -.EE -.RE +This is the Linux kernel "OOM-killer" keystroke. It shoots down random +long-running programs of its choosing, and so might target and kill +XScreenSaver. You can disable this keystroke globally with: +.nf +.sp + echo 176 > /proc/sys/kernel/sysrq +.sp +.fi There's little that I can do to make the screen locker be secure so long as the kernel and X11 developers are \fIactively\fP 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. -.TP 4 -.B 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 \fBRECORD, XTRAP\fP -or \fBXTEST\fP extensions, you absolutely should disable those, 100% -of the time. Look for them in \fIxorg.conf\fP or whatever it is -called. +.SS THE OOM-KILLER +Even if you have disabled the \fBAlt-SysRq-F\fP OOM-killer keystroke, the +OOM-killer might still decide to assassinate XScreenSaver at random, which +will unlock your screen. If the +.BR xscreensaver\-auth (MANSUFFIX) +program is installed setuid, it attempts to tell the OOM-killer to leave +the XScreenSaver daemon alone, but that may or may not work. + +You would think that the OOM-killer would pick the process using the most +memory, but most of the time it seems to pick the process that would be most +comically inconvenient, such as your screen locker, or +.BR crond (8). +You can disable the OOM-killer entirely with: +.nf +.sp + echo 2 > /proc/sys/vm/overcommit_memory + echo vm.overcommit_memory = 2 >> /etc/sysctl.conf +.sp +.fi + +.SS X SERVER ACCESS IS GAME OVER +X11's security model is all-or-nothing. If a program can connect to your X +server at all, either locally or over the network, it can log all of your +keystrokes, simulate keystrokes, launch arbitrary programs, and change the +settings of other programs. Assume that anything that can connect to your X +server can execute arbitrary code as the logged-in user. See +.BR Xsecurity (1) +and +.BR xauth (1). + +.SS PAM PASSWORDS +If your system uses PAM (Pluggable Authentication Modules), then PAM must be +configured for XScreenSaver. If it is not, then you \fImight\fP be in a +situation where you can't unlock. Probably the file you need +is \fI/etc/pam.d/xscreensaver\fP. + +.SS DON'T LOG IN AS ROOT +In order for it to be safe for XScreenSaver to be launched by \fIxdm\fP, +certain precautions had to be taken, among them that XScreenSaver never +runs as \fIroot\fP. In particular, if it is launched as root (as \fIxdm\fP +is likely to do), XScreenSaver will disavow its privileges, and switch +itself to a safe user id (such as \fInobody\fP). + +An implication of this is that if you log in as \fIroot\fP on the console, +XScreenSaver will refuse to lock the screen (because it can't tell +the difference between \fIroot\fP being logged in on the console, and a +normal user being logged in on the console but XScreenSaver having been +launched by the +.BR xdm (1) +.I Xsetup +file). + +Proper Unix hygiene dictates that you should log in as yourself, and +.BR sudo (1) +to \fIroot\fP as necessary. People who spend their day logged in +as \fIroot\fP are just begging for disaster. + +.SH MULTI-USER OR SITE-WIDE CONFIGURATION +For a single user, the proper way to configure XScreenSaver is to simply +run the +.BR xscreensaver\-settings (1) +program, and change the settings through the GUI. The rest of this manual +describes lower-level ways of changing settings. You shouldn't need to +know any of the stuff described below unless you are trying to do something +complicated. + +Options to XScreenSaver are stored in one of two places: in a file +called \fI.xscreensaver\fP 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 parameter +n the \fI.xscreensaver\fP file, you would write the following: +.nf +.sp + timeout: 5 +.sp +.fi +whereas, in the \fI.Xdefaults\fP file, you would write +.nf +.sp + xscreensaver.timeout: 5 +.sp +.fi +If you change a setting in the \fI.xscreensaver\fP file while XScreenSaver +is already running, it will notice this, and reload the file as needed. + +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 \fI.Xdefaults\fP file, and then +tell the running \fIxscreensaver\fP process to restart itself, like so: +.nf +.sp + xrdb < ~/.Xdefaults + xscreensaver-command \-\-restart +.sp +.fi +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 /etc/X11/app-defaults/XScreenSaver, but different +systems might keep it in a different place. + +When settings are changed in the Preferences dialog box, those settings are +written to the \fI.xscreensaver\fP file. The \fI.Xdefaults\fP file and the +app-defaults file will never be written by XScreenSaver itself. + .SH X RESOURCES -These are the X resources use by the \fIxscreensaver\fP program. -You probably won't need to change these manually (that's what the -.BR xscreensaver\-demo (1) -program is for). +These are the X resources use by XScreenSaver program. You probably won't +need to change these manually: that's what the +.BR xscreensaver\-settings (1) +program is for. + .TP 8 .B timeout\fP (class \fBTime\fP) The screensaver will activate (blank the screen) after the keyboard and mouse have been idle for this many minutes. Default 10 minutes. + .TP 8 .B cycle\fP (class \fBTime\fP) After the screensaver has been running for this many minutes, the currently @@ -562,46 +572,46 @@ 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 \fIcycle\fP minutes even when -\fImode\fP is \fIone\fP, since some savers tend to converge on a steady -state. +If there are multiple screens, the savers are staggered slightly so +that while they all change every \fIcycle\fP minutes, they don't all +change at the same time. + .TP 8 .B lock\fP (class \fBBoolean\fP) Enable locking: before the screensaver will turn off, it will require you -to type the password of the logged-in user (really, the person who ran -xscreensaver), or the root password. (\fBNote:\fP this doesn't work if the -screensaver is launched by -.BR xdm (1) -because it can't know the user-id of the logged-in user. See -the "\fIUsing XDM(1)\fP" section, below. +to type the password of the logged-in user. + .TP 8 .B lockTimeout\fP (class \fBTime\fP) If locking is enabled, this controls the length of the "grace period" between when the screensaver activates, and when the screen becomes locked. -For example, if this is 5, and \fI\-timeout\fP is 10, then after 10 minutes, +For example, if this is 5, and \fItimeout\fP 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, \fI\-lock\-timeout\fP minutes after +at 15 minutes or later (that is, \fIlockTimeout\fP minutes after activation) then a password would be required. The default is 0, meaning that if locking is enabled, then a password will be required as soon as the screen blanks. + .TP 8 .B passwdTimeout\fP (class \fBTime\fP) If the screen is locked, then this is how many seconds the password dialog box -should be left on the screen before giving up (default 30 seconds). This -should not be too large: the X server is grabbed for the duration that the -password dialog box is up (for security purposes) and leaving the server -grabbed for too long can cause problems. +should be left on the screen before giving up (default 30 seconds). A few +seconds are added each time you type a character. + .TP 8 .B dpmsEnabled\fP (class \fBBoolean\fP) Whether power management is enabled. + .TP 8 .B dpmsStandby\fP (class \fBTime\fP) If power management is enabled, how long until the monitor goes solid black. + .TP 8 .B dpmsSuspend\fP (class \fBTime\fP) If power management is enabled, how long until the monitor goes into power-saving mode. + .TP 8 .B dpmsOff\fP (class \fBTime\fP) If power management is enabled, how long until the monitor powers down @@ -609,109 +619,42 @@ completely. Note that these settings will have no effect unless both the X server and the display hardware support power management; not all do. See the \fIPower Management\fP section, below, for more information. + .TP 8 .B dpmsQuickOff\fP (class \fBBoolean\fP) If \fImode\fP is \fIblank\fP and this is true, then the screen will be powered down immediately upon blanking, regardless of other power-management settings. -.TP 8 -.B visualID\fP (class \fBVisualID\fP) -This is an historical artifacts left over from when 8-bit -displays were still common. You should probably ignore this. -Specify which X visual to use by default. (Note carefully that this resource -is called \fBvisualID\fP, not merely \fBvisual\fP; if you set the \fBvisual\fP -resource instead, things will malfunction in obscure ways for obscure reasons.) - -Legal values for the \fBVisualID\fP resource are: -.RS 8 -.TP 8 -.B default -Use the screen's default visual (the visual of the root window). -This is the default. -.TP 8 -.B best -Use the visual which supports the most colors. Note, however, that the -visual with the most colors might be a TrueColor visual, which does not -support colormap animation. Some programs have more interesting behavior -when run on PseudoColor visuals than on TrueColor. -.TP 8 -.B mono -Use a monochrome visual, if there is one. -.TP 8 -.B gray -Use a grayscale or staticgray visual, if there is one and it has more than -one plane (that is, it's not monochrome). -.TP 8 -.B color -Use the best of the color visuals, if there are any. -.TP 8 -.B GL -Use the visual that is best for OpenGL programs. (OpenGL programs have -somewhat different requirements than other X programs.) -.TP 8 -.I class -where \fIclass\fP is one of \fBStaticGray\fP, \fBStaticColor\fP, -\fBTrueColor\fP, \fBGrayScale\fP, \fBPseudoColor\fP, or \fBDirectColor\fP. -Selects the deepest visual of the given class. -.TP 8 -.I number -where \fInumber\fP (decimal or hex) is interpreted as a visual id number, -as reported by the -.BR xdpyinfo (1) -program; in this way you can have finer control over exactly which visual -gets used, for example, to select a shallower one than would otherwise -have been chosen. - -.RE -.RS 8 -Note that this option specifies only the \fIdefault\fP visual that will -be used: the visual used may be overridden on a program-by-program basis. -See the description of the \fBprograms\fP resource, below. -.RE -.TP 8 -.B installColormap\fP (class \fBBoolean\fP) -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 automatically.) This can also be overridden on a -per-hack basis: see the discussion of the \fBdefault\-n\fP name in the -section about the \fBprograms\fP resource. - -This does nothing if you have a TrueColor (16-bit or deeper) display. -(Which, in this century, you do.) .TP 8 .B verbose\fP (class \fBBoolean\fP) Whether to print diagnostics. Default false. -.TP 8 -.B timestamp\fP (class \fBBoolean\fP) -Whether to print the time of day along with any other diagnostic messages. -Default true. + .TP 8 .B splash\fP (class \fBBoolean\fP) Whether to display a splash screen at startup. Default true. + .TP 8 .B splashDuration\fP (class \fBTime\fP) How long the splash screen should remain visible; default 5 seconds. + .TP 8 .B helpURL\fP (class \fBURL\fP) The splash screen has a \fIHelp\fP button on it. When you press it, it will display the web page indicated here in your web browser. + .TP 8 .B loadURL\fP (class \fBLoadURL\fP) This is the shell command used to load a URL into your web browser. The default setting will load it into Mozilla/Netscape if it is already running, otherwise, will launch a new browser 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 -.BR xscreensaver\-demo (1). -.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. +.BR xscreensaver\-settings (1). + .TP 8 .B newLoginCommand\fP (class \fBNewLoginCommand\fP) If set, this is the shell command that is run when the "New Login" button @@ -723,104 +666,92 @@ Typically this will be some variant of .BR lxdm (1) or .BR dm-tool (1). + .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 -system, and don't increase the load unnecessarily. The default is 10. -(Higher numbers mean lower priority; see +The sub-processes launched 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 unnecessarily. The default is 10. (Higher numbers +mean lower priority; see .BR nice (1) for details.) + .TP 8 .B fade\fP (class \fBBoolean\fP) If this is true, then when the screensaver activates, the current contents -of the screen will fade to black instead of simply winking out. This only -works on certain systems. A fade will also be done when switching graphics -hacks (when the \fIcycle\fP timer expires). Default: true. +of the screen will fade to black instead of simply winking out. +Default: true. + .TP 8 .B unfade\fP (class \fBBoolean\fP) If this is true, then when the screensaver deactivates, the original contents of the screen will fade in from black instead of appearing immediately. This -only works on certain systems, and if \fIfade\fP is true as well. -Default false. +is only done if \fIfade\fP is true as well. Default: true. + .TP 8 .B fadeSeconds\fP (class \fBTime\fP) If \fIfade\fP is true, this is how long the fade will be in -seconds (default 3 seconds). -.TP 8 -.B fadeTicks\fP (class \fBInteger\fP) -If \fIfade\fP is true, this is how many times a second the colormap will -be changed to effect a fade. Higher numbers yield smoother fades, but -may make the fades take longer than the specified \fIfadeSeconds\fP if -your server isn't fast enough to keep up. Default 20. -.TP 8 -.B captureStderr\fP (class \fBBoolean\fP) -Whether \fIxscreensaver\fP should redirect its stdout and stderr streams to -the window itself. Since its nature is to take over the screen, you would not -normally see error messages generated by xscreensaver or the sub-programs it -runs; this resource will cause the output of all relevant programs to be -drawn on the screensaver window itself, as well as being written to the -controlling terminal of the screensaver driver process. Default true. +seconds. Default 3 seconds. + .TP 8 .B ignoreUninstalledPrograms\fP (class \fBBoolean\fP) 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 -.BR xscreensaver-demo (1) +.BR xscreensaver\-settings (1) program will suppress the non-existent programs from the list if this is true. Default: false. + .TP 8 .B authWarningSlack\fP (class \fBInteger\fP) -If \fIall\fP 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 suppressed. The assumption +After you successfully unlock the screen, a dialog may pop up informing +you of previous failed login attempts. If all of those login attemps +were within this amount of time, they are ignored. 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. -.TP 8 -.B GetViewPortIsFullOfLies\fP (class \fBBoolean\fP) -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. -.TP 8 -.B font\fP (class \fBFont\fP) -The font used for the stdout/stderr text, if \fBcaptureStderr\fP is true. -Default \fB*\-medium\-r\-*\-140\-*\-m\-*\fP (a 14 point fixed-width font). + .TP 8 .B mode\fP (class \fBMode\fP) -Controls the behavior of xscreensaver. Legal values are: +Controls the screen-saving behavior. Valid values are: .RS 8 + .TP 8 .B random When blanking the screen, select a random display mode from among those that are enabled and applicable. This is the default. + .TP 8 .B random-same Like \fIrandom\fP, but if there are multiple screens, each screen will run the \fIsame\fP random display mode, instead of each screen running a different one. + .TP 8 .B one When blanking the screen, only ever use one particular display mode (the one indicated by the \fIselected\fP setting). + .TP 8 .B blank When blanking the screen, just go black: don't run any graphics hacks. + .TP 8 .B off Don't ever blank the screen, and don't ever allow the monitor to power down. - .RE + .TP 8 .B selected\fP (class \fBInteger\fP) When \fImode\fP is set to \fIone\fP, this is the one, indicated by its index in the \fIprograms\fP list. You're crazy if you count them and set this number by hand: let -.BR xscreensaver\-demo (1) +.BR xscreensaver\-settings (1) do it for you! + .TP 8 .B programs\fP (class \fBPrograms\fP) -The graphics hacks which \fIxscreensaver\fP runs when the user is idle. +The graphics hacks which XScreenSaver runs when the user is idle. The value of this resource is a multi-line string, one \fIsh\fP-syntax command per line. Each line must contain exactly one command: no semicolons, no ampersands. @@ -832,7 +763,7 @@ 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 -.BR xscreensaver\-demo (1) +.BR xscreensaver\-settings (1) program). If all programs are disabled, then the screen will just be made blank, @@ -850,32 +781,28 @@ 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 \fI~/.xscreensaver\fP file: - -.RS 8 -.EX -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 +.nf +.sp + programs: \\ + qix -root \\n\\ + ico -r -faces -sleep 1 -obj ico \\n\\ + xdaliclock -builtin2 -root \\n\\ + xv -root -rmode 5 image.gif -quit \\n +.sp +.fi .RS 8 Make sure your \fB$PATH\fP environment variable is set up correctly -\fIbefore\fP xscreensaver is launched, or it won't be able to find the +\fIbefore\fP XScreenSaver is launched, or it won't be able to find the programs listed in the \fIprograms\fP resource. -To use a program as a screensaver, two things are required: that that -program draw on the root window (or be able to be configured to draw on -the root window); and that that program understand "virtual root" -windows, as used by virtual window managers such as -.BR tvtwm (1). -(Generally, this is accomplished by just including the \fI"vroot.h"\fP -header file in the program's source.) +To use a program as a screensaver, it must be able to render onto +the window provided to it in the \fB$XSCREENSAVER_WINDOW\fP environment +variable. If it creates and maps its own window instead, it won't work. +It must render onto the provided window. .B Visuals: -Because xscreensaver was created back when dinosaurs roamed the earth, +Because XScreenSaver was created back when dinosaurs roamed the earth, it still contains support for some things you've probably never seen, such as 1-bit monochrome monitors, grayscale monitors, and monitors capable of displaying only 8-bit colormapped images. @@ -883,22 +810,22 @@ capable of displaying only 8-bit colormapped 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: -.EX - mono: mono-program -root \\n\\ - color: color-program -root \\n\\ -.EE -.RE -.RS 8 +.nf +.sp + mono: mono-program -root \\n\\ + color: color-program -root \\n\\ +.sp +.fi 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: -.EX - PseudoColor: cmap-program -root \\n\\ - TrueColor: 24bit-program -root \\n\\ -.EE -.RE -.RS 8 +.nf +.sp + PseudoColor: cmap-program -root \\n\\ + TrueColor: 24bit-program -root \\n\\ +.sp +.fi 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: @@ -906,15 +833,7 @@ the \fIprograms\fP list: .TP 4 .B default-n This is like \fBdefault\fP, but also requests the use of the default colormap, -instead of a private colormap. (That is, it behaves as if -the \fI\-no\-install\fP command-line option was specified, but only for -this particular hack.) This is provided because some third-party programs -that draw on the root window (notably: -.BR xv (1), -and -.BR xearth (1)) -make assumptions about the visual and colormap of the root window: -assumptions which xscreensaver can violate. +instead of a private colormap. .RE If you specify a particular visual for a program, and that visual does not @@ -924,72 +843,88 @@ 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. .RE -.PP -.PP -You shouldn't ever need to change the following resources: -.PP + .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. +.B visualID\fP (class \fBVisualID\fP) +This is an historical artifact left over from when 8-bit +displays were still common. You should probably ignore this. + +Specify which X visual to use by default. (Note carefully that this resource +is called \fBvisualID\fP, not merely \fBvisual\fP; if you set the \fBvisual\fP +resource instead, things will malfunction in obscure ways for obscure reasons.) + +Valid values for the \fBVisualID\fP resource are: +.RS 8 .TP 8 -.B pointerHysteresis\fP (class \fBInteger\fP) -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. +.B default +Use the screen's default visual (the visual of the root window). +This is the default. +.TP 8 +.B best +Use the visual which supports the most colors. Note, however, that the +visual with the most colors might be a TrueColor visual, which does not +support colormap animation. Some programs have more interesting behavior +when run on PseudoColor visuals than on TrueColor. +.TP 8 +.B mono +Use a monochrome visual, if there is one. .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. +.B gray +Use a grayscale or staticgray visual, if there is one and it has more than +one plane (that is, it's not monochrome). .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 -\fIxscreensaver\fP 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...) +.B color +Use the best of the color visuals, if there are any. .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. +.B GL +Use the visual that is best for OpenGL programs. (OpenGL programs have +somewhat different requirements than other X programs.) .TP 8 -.B overlayStderr\fP (class \fBBoolean\fP) -If \fBcaptureStderr\fP is True, and your server supports "overlay" visuals, -then the text will be written into one of the higher layers instead of into -the same layer as the running screenhack. Set this to False to disable -that (though you shouldn't need to). +.I class +where \fIclass\fP is one of \fBStaticGray\fP, \fBStaticColor\fP, +\fBTrueColor\fP, \fBGrayScale\fP, \fBPseudoColor\fP, or \fBDirectColor\fP. +Selects the deepest visual of the given class. .TP 8 -.B overlayTextForeground\fP (class \fBForeground\fP) -The foreground color used for the stdout/stderr text, if \fBcaptureStderr\fP -is true. Default: Yellow. +.I N +where \fInumber\fP (decimal or hex) is interpreted as a visual id number, +as reported by the +.BR xdpyinfo (1) +program; in this way you can have finer control over exactly which visual +gets used, for example, to select a shallower one than would otherwise +have been chosen. + +.RE +.RS 8 +Note that this option specifies only the \fIdefault\fP visual that will +be used: the visual used may be overridden on a program-by-program basis. +See the description of the \fBprograms\fP resource, above. +.RE + .TP 8 -.B overlayTextBackground\fP (class \fBBackground\fP) -The background color used for the stdout/stderr text, if \fBcaptureStderr\fP -is true. Default: Black. +.B installColormap\fP (class \fBBoolean\fP) +This is an historical artifact left over from when 8-bit displays were still +common. 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 +automatically.) This can also be overridden on a per-hack basis: see the +discussion of the \fBdefault\-n\fP name in the section about the +\fBprograms\fP resource. + +This does nothing if you have a TrueColor (16-bit or deeper) display. +(Which, in this century, you do.) + .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 pointerHysteresis\fP (class \fBInteger\fP) +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. + +.SH BUGS +https://www.jwz.org/xscreensaver/bugs.html explains how to write the most +useful bug reports. If you find a bug, please let me know! + .SH ENVIRONMENT .PP .TP 8 @@ -1003,7 +938,7 @@ should draw. This is necessary on Xinerama/RANDR systems where multiple physical monitors share a single X11 "Screen". .TP 8 .B PATH -to find the sub-programs to run. +to find the sub-programs to run, including the display modes. .TP 8 .B HOME for the directory in which to read the \fI.xscreensaver\fP file. @@ -1012,7 +947,7 @@ for the directory in which to read the \fI.xscreensaver\fP file. to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property. .SH UPGRADES -The latest version of xscreensaver, an online version of this manual, +The latest version of XScreenSaver, an online version of this manual, and a FAQ can always be found at https://www.jwz.org/xscreensaver/ .SH SEE ALSO .BR X (1), @@ -1021,13 +956,16 @@ and a FAQ can always be found at https://www.jwz.org/xscreensaver/ .BR xdm (1), .BR gdm (1), .BR xhost (1), -.BR xscreensaver\-demo (1), +.BR systemd (1), +.BR elogind (8), +.BR xscreensaver\-settings (1), .BR xscreensaver\-command (1), -.BR xscreensaver\-gl\-helper (1), -.BR xscreensaver\-getimage (1), -.BR xscreensaver\-text (1). +.BR xscreensaver\-systemd (MANSUFFIX), +.BR xscreensaver\-gl\-helper (MANSUFFIX), +.BR xscreensaver\-getimage (MANSUFFIX), +.BR xscreensaver\-text (MANSUFFIX). .SH COPYRIGHT -Copyright \(co 1991-2019 by Jamie Zawinski. +Copyright \(co 1991-2021 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 @@ -1042,5 +980,5 @@ 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! +large ways and small, to the XScreenSaver collection over the past +three decades! |