XScreenSaver(1) XScreenSaver(1) NNAAMMEE xscreensaver - graphics hack and screen locker, launched when the user is idle SSYYNNOOPPSSIISS xxssccrreeeennssaavveerr [-display _h_o_s_t_:_d_i_s_p_l_a_y_._s_c_r_e_e_n] [-timeout _i_n_t] [-cycle _i_n_t] [-lock-mode] [-no-lock-mode] [-lock-timeout _i_n_t] [-visual _v_i_s_u_a_l] [-install] [-no-install] [-verbose] [-silent] [-timestamp] [-capture-stderr] [-no-cap- ture-stderr] [-splash] [-no-splash] [-nice _i_n_t] [-mit-extension] [-no-mit-extension] [-sgi-extension] [-no-sgi-extension] [-xidle-extension] [-no-xidle-exten- sion] [-proc-interrupts] [-no-proc-interrupts] [-xrm _r_e_s_o_u_r_c_e_s] DDEESSCCRRIIPPTTIIOONN The _x_s_c_r_e_e_n_s_a_v_e_r program waits until the keyboard and mouse have been idle for a period, and then runs a graph- ics 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. The benefit that this program has over the combination of the xxlloocckk(1) and xxaauuttoolloocckk(1) programs is the ease with which new graphics hacks can be installed. You don't need to recompile (or even re-run) this program to add a new display mode. GGEETTTTIINNGG SSTTAARRTTEEDD For the impatient, try this: xscreensaver & xscreensaver-demo The xxssccrreeeennssaavveerr--ddeemmoo(1) program should pop up a dialog box that lets you experiment with the xscreensaver set- tings and graphics modes. NNoottee:: unlike xxlloocckk(1), xscreensaver has a client-server model: the _x_s_c_r_e_e_n_s_a_v_e_r program is a daemon that runs in the background; it is controlled by the foreground xxssccrreeeennssaavveerr--ddeemmoo(1) and xxssccrreeeennssaavveerr--ccoommmmaanndd(1) programs. CCOONNFFIIGGUURRAATTIIOONN Options to _x_s_c_r_e_e_n_s_a_v_e_r are specified in one of two places: in a _._x_s_c_r_e_e_n_s_a_v_e_r file in your home directory; or in the X resource database. If the _._x_s_c_r_e_e_n_s_a_v_e_r file exists, it overrides any settings in the resource database. X Version 11 20-Jun-99 (3.15) 1 XScreenSaver(1) XScreenSaver(1) The syntax of the _._x_s_c_r_e_e_n_s_a_v_e_r file is similar to that of the _._X_d_e_f_a_u_l_t_s file; for example, to set the _t_i_m_e_o_u_t paramter in the _._x_s_c_r_e_e_n_s_a_v_e_r file, you would write the following: timeout: 5 whereas, in the _._X_d_e_f_a_u_l_t_s file, you would write xscreensaver.timeout: 5 If you change a setting in the _._x_s_c_r_e_e_n_s_a_v_e_r 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 blank- ing 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: xscreensaver-command -restart Note that if you changed the _._X_d_e_f_a_u_l_t_s file, you might also need to run xxrrddbb(1): xrdb < ~/.Xdefaults 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 sys- tems 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 _._x_s_c_r_e_e_n_s_a_v_e_r file. (The _._X_d_e_f_a_u_l_t_s file and the app- defaults file will never be written by xscreensaver itself.) ttiimmeeoouutt (class TTiimmee) The screensaver will activate (blank the screen) after the keyboard and mouse have been idle for this many minutes. Default 10 minutes. ccyyccllee (class TTiimmee) After the screensaver has been running for this many minutes, the currently running graphics-hack X Version 11 20-Jun-99 (3.15) 2 XScreenSaver(1) XScreenSaver(1) sub-process will be killed (with SSIIGGTTEERRMM), and a new one started. If this is 0, then the graphics hack will never be changed: only one demo will run until the screensaver is deactivated by user activity. Default 10 minutes. lloocckk (class BBoooolleeaann) 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. (NNoottee:: this doesn't work if the screensaver is launched by xxddmm(1) because it can't know the user-id of the logged-in user. See the ``_U_s_i_n_g _X_D_M_(_1_)'' section, below. lloocckkTTiimmeeoouutt (class TTiimmee) 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 _-_t_i_m_e_o_u_t 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, _-_l_o_c_k_-_t_i_m_e_o_u_t 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. ppaasssswwddTTiimmeeoouutt (class TTiimmee) 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. vviissuuaallIIDD (class VViissuuaallIIDD) Specify which X visual to use by default. (Note carefully that this resource is called vviissuuaallIIDD, not merely vviissuuaall; if you set the vviissuuaall resource instead, things will malfunction in obscure ways for obscure reasons.) Legal values for the VViissuuaallIIDD resource are: ddeeffaauulltt Use the screen's default visual (the visual of the root window.) This is the default. bbeesstt Use the visual which supports the most X Version 11 20-Jun-99 (3.15) 3 XScreenSaver(1) XScreenSaver(1) 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 inter- esting behavior when run on PseudoColor visuals than on TrueColor. mmoonnoo Use a monochrome visual, if there is one. ggrraayy Use a grayscale or staticgray visual, if there is one and it has more than one plane (that is, it's not monochrome.) ccoolloorr Use the best of the color visuals, if there are any. GGLL Use the visual that is best for OpenGL programs. (OpenGL programs have somewhat different requirements than other X pro- grams.) _c_l_a_s_s where _c_l_a_s_s is one of SSttaattiiccGGrraayy, SSttaattiicc-- CCoolloorr, TTrruueeCCoolloorr, GGrraayySSccaallee, PPsseeuuddooCCoolloorr, or DDiirreeccttCCoolloorr. Selects the deepest visual of the given class. _n_u_m_b_e_r where _n_u_m_b_e_r (decimal or hex) is inter- preted as a visual id number, as reported by the xxddppyyiinnffoo(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 other- wise have been chosen. Note that this option specifies only the _d_e_f_a_u_l_t visual that will be used: the visual used may be overridden on a program-by-program basis. See the description of the pprrooggrraammss resource, below. iinnssttaallllCCoolloorrmmaapp (class BBoooolleeaann) 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 ddeeffaauulltt--nn name in the section about the pprrooggrraammss resource. vveerrbboossee (class BBoooolleeaann) Whether to print diagnostics. Default false. X Version 11 20-Jun-99 (3.15) 4 XScreenSaver(1) XScreenSaver(1) ttiimmeessttaammpp (class BBoooolleeaann) Whether to print the time of day along with any other diagnostic messages. Default false. ssppllaasshh (class BBoooolleeaann) Whether to display a splash screen at startup. Default true. ssppllaasshhDDuurraattiioonn (class TTiimmee) How long the splash screen should remain visible; default 5 seconds. hheellppUURRLL (class UURRLL) The splash screen has a _H_e_l_p button on it. When you press it, it will display the web page indi- cated here in your web browser. llooaaddUURRLL (class LLooaaddUURRLL) This is the shell command used to load a URL into your web browser. The default setting will load it into Netscape if it is already running, other- wise, will launch a new Netscape looking at the _h_e_l_p_U_R_L. ddeemmooCCoommmmaanndd (class DDeemmooCCoommmmaanndd) This is the shell command run when the _D_e_m_o button on the splash window is pressed. It defaults to _x_s_c_r_e_e_n_s_a_v_e_r_-_d_e_m_o. pprreeffssCCoommmmaanndd (class PPrreeffssCCoommmmaanndd) This is the shell command run when the _P_r_e_f_s but- ton on the splash window is pressed. It defaults to _x_s_c_r_e_e_n_s_a_v_e_r_-_d_e_m_o _-_p_r_e_f_s. nniiccee (class NNiiccee) The sub-processes created by _x_s_c_r_e_e_n_s_a_v_e_r 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 nniiccee(1) for details.) ffaaddee (class BBoooolleeaann) If this is true, then when the screensaver acti- vates, the current contents of the screen will fade to black instead of simply winking out. This only works on displays with writable colormaps, that is, if the screen's default visual is a Pseu- doColor visual. A fade will also be done when switching graphics hacks (when the _c_y_c_l_e timer expires.) Default: true. X Version 11 20-Jun-99 (3.15) 5 XScreenSaver(1) XScreenSaver(1) uunnffaaddee (class BBoooolleeaann) If this is true, then when the screensaver deacti- vates, the original contents of the screen will fade in from black instead of appearing immedi- ately. This only works on displays with writable colormaps, and if _f_a_d_e is true as well. Default false. ffaaddeeSSeeccoonnddss (class TTiimmee) If _f_a_d_e is true, this is how long the fade will be in seconds (default 3 seconds.) ffaaddeeTTiicckkss (class IInntteeggeerr) If _f_a_d_e 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 _f_a_d_e_S_e_c_- _o_n_d_s if your server isn't fast enough to keep up. Default 20. ccaappttuurreeSSttddeerrrr (class BBoooolleeaann) Whether _x_s_c_r_e_e_n_s_a_v_e_r 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 control- ling terminal of the screensaver driver process. Default true. ffoonntt (class FFoonntt) The font used for the stdout/stderr text, if ccaapp-- ttuurreeSSttddeerrrr is true. Default **--mmeeddiiuumm--rr--**--114400--**--mm--** (a 14 point fixed-width font.) pprrooggrraammss (class PPrrooggrraammss) The graphics hacks which _x_s_c_r_e_e_n_s_a_v_e_r runs when the user is idle. The value of this resource is a string, one _s_h-syntax command per line. Each line must contain exactly one command: no semicolons, no ampersands. When the screensaver starts up, one of these is selected at random, and run. After the _c_y_c_l_e period expires, it is killed, and another is selected and run. If the value of this resource is empty, then no programs will be run; the screen will simply be made black. X Version 11 20-Jun-99 (3.15) 6 XScreenSaver(1) XScreenSaver(1) If the display has multiple screens, then a dif- ferent program will be run for each screen. (All screens are blanked and unblanked simultaniously.) Note that you must escape the newlines; here is an example of how you might set this in your _~_/_._x_s_c_r_e_e_n_s_a_v_e_r file: programs: \ qix -root \n\ ico -r -faces -sleep 1 -obj ico \n\ xdaliclock -builtin2 -root \n\ xv -root -rmode 5 image.gif -quit \n Make sure your $$PPAATTHH environment variable is set up correctly _b_e_f_o_r_e xscreensaver is launched, or it won't be able to find the programs listed in the _p_r_o_g_r_a_m_s resource. To use a program as a screensaver, two things are required: that that program draw on the root win- dow (or be able to be configured to draw on the root window); and that that program understand ``virtual root'' windows, as used by virtual win- dow managers such as ttvvttwwmm(1). (Generally, this is accomplished by just including the _"_v_r_o_o_t_._h_" 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 dis- play, you can specify that like this: mono: mono-program -root \n\ color: color-program -root \n\ More generally, you can specify the kind of visual that should be used for the window on which the program will be drawing. For example, if one pro- gram works best if it has a colormap, but another works best if it has a 24-bit visual, both can be accommodated: PseudoColor: cmap-program -root \n\ TrueColor: 24bit-program -root \n\ In addition to the symbolic visual names described above (in the discussion of the _v_i_s_u_a_l_I_D resource) one other visual name is supported in the _p_r_o_g_r_a_m_s list: ddeeffaauulltt--nn This is like ddeeffaauulltt, but also requests the X Version 11 20-Jun-99 (3.15) 7 XScreenSaver(1) XScreenSaver(1) use of the default colormap, instead of a private colormap. (That is, it behaves as if the _-_n_o_-_i_n_s_t_a_l_l command-line option was spec- ified, but only for this particular hack.) This is provided because some third-party programs that draw on the root window (notably: xxvv(1), and xxeeaarrtthh(1)) make assump- tions about the visual and colormap of the root window: assumptions which xscreensaver can violate. If you specify a particular visual for a program, and that visual does not exist on the screen, then that program will not be chosen to run. This means that on displays with multiple screens of different depths, you can arrange for appropriate hacks to be run on each. For example, if one screen is color and the other is monochrome, hacks that look good in mono can be run on one, and hacks that only look good in color will show up on the other. Normally you won't need to change the following resources: ppooiinntteerrPPoollllTTiimmee (class TTiimmee) When server extensions are not in use, this con- trols how frequently _x_s_c_r_e_e_n_s_a_v_e_r checks to see if the mouse position or buttons have changed. Default 5 seconds. wwiinnddoowwCCrreeaattiioonnTTiimmeeoouutt (class TTiimmee) When server extensions are not in use, this con- trols the delay between when windows are created and when _x_s_c_r_e_e_n_s_a_v_e_r selects events on them. Default 30 seconds. iinniittiiaallDDeellaayy (class TTiimmee) When server extensions are not in use, _x_s_c_r_e_e_n_- _s_a_v_e_r will wait this many seconds before selecting events on existing windows, under the assumption that _x_s_c_r_e_e_n_s_a_v_e_r 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 ter- minals were more common...) ssggiiSSaavveerrEExxtteennssiioonn (class BBoooolleeaann) There are a number of different X server exten- sions which can make xscreensaver's job easier. The next few resources specify whether these extensions should be utilized if they are avail- able. X Version 11 20-Jun-99 (3.15) 8 XScreenSaver(1) XScreenSaver(1) This resource controls whether the SGI SSCCRREEEENN__SSAAVVEERR server extension will be used to decide whether the user is idle. This is the default if _x_s_c_r_e_e_n_s_a_v_e_r has been compiled with support for this extension (which is the default on SGI systems.). If it is available, the SSCCRREEEENN__SSAAVVEERR 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.) mmiittSSaavveerrEExxtteennssiioonn (class BBoooolleeaann) This resource controls whether the MMIITT--SSCCRREEEENN--SSAAVVEERR server extension will be used to decide whether the user is idle. However, the default for this resource is _f_a_l_s_e, because even if this extension is available, it is flaky (and it also makes the ffaaddee option not work properly.) Use of this extension is not recommended. xxiiddlleeEExxtteennssiioonn (class BBoooolleeaann) This resource controls whether the XXIIDDLLEE server extension will be used to decide whether the user is idle. This is the default if _x_s_c_r_e_e_n_s_a_v_e_r has been compiled with support for this extension. (This extension is only available for X11R4 and X11R5 systems, unfortunately.) pprrooccIInntteerrrruuppttss (class BBoooolleeaann) This resource controls whether the //pprroocc//iinntteerr-- rruuppttss file should be consulted to decide whether the user is idle. This is the default if _x_s_c_r_e_e_n_- _s_a_v_e_r has been compiled on a system which supports this mechanism (i.e., Linux systems.) The benefit to doing this is that _x_s_c_r_e_e_n_s_a_v_e_r can note that the user is active even when the X con- sole is not the active one: if the user is typing in another virtual console, xscreensaver will notice that and will fail to activate. For exam- ple, if you're playing Quake in VGA-mode, xscreen- saver won't wake up in the middle of your game and start competing for CPU. The drawback to doing this is that perhaps you _r_e_a_l_l_y _d_o 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. X Version 11 20-Jun-99 (3.15) 9 XScreenSaver(1) XScreenSaver(1) oovveerrllaayySSttddeerrrr (class BBoooolleeaann) If ccaappttuurreeSSttddeerrrr 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.) oovveerrllaayyTTeexxttFFoorreeggrroouunndd (class FFoorreeggrroouunndd) The foreground color used for the stdout/stderr text, if ccaappttuurreeSSttddeerrrr is true. Default: Yellow. oovveerrllaayyTTeexxttBBaacckkggrroouunndd (class BBaacckkggrroouunndd) The background color used for the stdout/stderr text, if ccaappttuurreeSSttddeerrrr is true. Default: Black. bboouurrnneeSShheellll (class BBoouurrnneeSShheellll) The pathname of the shell that _x_s_c_r_e_e_n_s_a_v_e_r uses to start subprocesses. This must be whatever your local variant of //bbiinn//sshh is: in particular, it must not be ccsshh. CCOOMMMMAANNDD--LLIINNEE OOPPTTIIOONNSS _x_s_c_r_e_e_n_s_a_v_e_r also accepts the following command line options. Except for the _-_d_i_s_p_l_a_y option, these command- line options are all simply shorthand for the X resources described in the _C_o_n_f_i_g_u_r_a_t_i_o_n section, above. --ddiissppllaayy _h_o_s_t_:_d_i_s_p_l_a_y_._s_c_r_e_e_n The X display to use. For displays with multiple screens, XScreenSaver will manage all screens on the display simultaniously; the _s_c_r_e_e_n argument (the ``default'' screen) says which screen should be used for dialog boxes (the password window, _D_e_m_o _M_o_d_e, etc.) --ttiimmeeoouutt _m_i_n_u_t_e_s Same as the _t_i_m_e_o_u_t resource. --ccyyccllee _m_i_n_u_t_e_s Same as the _c_y_c_l_e resource. --lloocckk--mmooddee Same as setting the _l_o_c_k resource to _t_r_u_e. --nnoo--lloocckk--mmooddee Same as setting the _l_o_c_k resource to _f_a_l_s_e. --lloocckk--ttiimmeeoouutt _m_i_n_u_t_e_s Same as the _l_o_c_k_T_i_m_e_o_u_t resource. --vviissuuaall _v_i_s_u_a_l Same as the _v_i_s_u_a_l_I_D resource. X Version 11 20-Jun-99 (3.15) 10 XScreenSaver(1) XScreenSaver(1) --iinnssttaallll Same as setting the _i_n_s_t_a_l_l_C_o_l_o_r_m_a_p resource to _t_r_u_e. --nnoo--iinnssttaallll Same as setting the _i_n_s_t_a_l_l_C_o_l_o_r_m_a_p resource to _f_a_l_s_e. --vveerrbboossee Same as setting the _v_e_r_b_o_s_e resource to _t_r_u_e. --ssiilleenntt Same as setting the _v_e_r_b_o_s_e resource to _f_a_l_s_e. --ttiimmeessttaammpp Same as setting the _t_i_m_e_s_t_a_m_p resource to _t_r_u_e. --ccaappttuurree--ssttddeerrrr Same as setting the _c_a_p_t_u_r_e_S_t_d_e_r_r resource to _t_r_u_e. --nnoo--ccaappttuurree--ssttddeerrrr Same as setting the _c_a_p_t_u_r_e_S_t_d_e_r_r resource to _f_a_l_s_e. --ssppllaasshh Same as setting the _s_p_l_a_s_h resource to _t_r_u_e. --nnoo--ssppllaasshh Same as setting the _s_p_l_a_s_h resource to _f_a_l_s_e. --nniiccee _i_n_t_e_g_e_r Same as the _n_i_c_e resource. --ssggii--eexxtteennssiioonn Same as setting the _s_g_i_S_a_v_e_r_E_x_t_e_n_s_i_o_n resource to _t_r_u_e. --nnoo--ssggii--eexxtteennssiioonn Same as setting the _s_g_i_S_a_v_e_r_E_x_t_e_n_s_i_o_n resource to _f_a_l_s_e. --mmiitt--eexxtteennssiioonn Same as setting the _m_i_t_S_a_v_e_r_E_x_t_e_n_s_i_o_n resource to _t_r_u_e. --nnoo--mmiitt--eexxtteennssiioonn Same as setting the _m_i_t_S_a_v_e_r_E_x_t_e_n_s_i_o_n resource to _f_a_l_s_e. --xxiiddllee--eexxtteennssiioonn Same as setting the _x_i_d_l_e_E_x_t_e_n_s_i_o_n resource to _t_r_u_e. --nnoo--xxiiddllee--eexxtteennssiioonn Same as setting the _x_i_d_l_e_E_x_t_e_n_s_i_o_n resource to X Version 11 20-Jun-99 (3.15) 11 XScreenSaver(1) XScreenSaver(1) _f_a_l_s_e. --pprroocc--iinntteerrrruuppttss Same as setting the _p_r_o_c_I_n_t_e_r_r_u_p_t_s resource to _t_r_u_e. --nnoo--pprroocc--iinntteerrrruuppttss Same as setting the _p_r_o_c_I_n_t_e_r_r_u_p_t_s resource to _f_a_l_s_e. --xxrrmm _r_e_s_o_u_r_c_e_-_s_p_e_c_i_f_i_c_a_t_i_o_n As with all other Xt programs, you can specify X resources on the command-line using the _-_x_r_m argu- ment. Most of the interesting resources have com- mand-line equivalents, however. HHOOWW IITT WWOORRKKSS 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 subse- quently-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 win- dows are unmapped, and the running subprocesses are killed by sending them SSIIGGTTEERRMM. This is also how the subpro- cesses are killed when the screensaver decides that it's time to run a different demo: the old one is killed and a new one is launched. Before launching a subprocess, _x_s_c_r_e_e_n_s_a_v_e_r stores an appropriate value for $$DDIISSPPLLAAYY in the environment that the child will recieve. (This is so that if you start _x_s_c_r_e_e_n_s_a_v_e_r with a _-_d_i_s_p_l_a_y argument, the programs which _x_s_c_r_e_e_n_s_a_v_e_r launches will draw on the same display; and so that the child will end up drawing on the appropriate screen of a multi-headed display.) When the screensaver turns off, or is killed, care is taken to restore the ``real'' virtual root window if there is one. Because of this, it is important that you not kill the screensaver process with _k_i_l_l _-_9 if you are run- ning a virtual-root window manager. If you kill it with -9, you may need to restart your window manager to repair the damage. This isn't an issue if you aren't running a virtual-root window manager. For all the gory details, see the commentary at the top of xscreensaver.c. You can control a running screensaver process by using the xxssccrreeeennssaavveerr--ccoommmmaanndd(1) program (which see.) X Version 11 20-Jun-99 (3.15) 12 XScreenSaver(1) XScreenSaver(1) PPOOWWEERR MMAANNAAGGEEMMEENNTT Modern X servers contain support to power down the monitor after an idle period. If the monitor has powered down, then _x_s_c_r_e_e_n_s_a_v_e_r will notice this, and will not waste CPU by drawing graphics demos on a black screen. An attempt will also be made to explicitly power the monitor back up as soon as user activity is detected. If your X server supports power management, then xxsseett(1) will accept a ddppmmss option. So, if you wanted _x_s_c_r_e_e_n_s_a_v_e_r to activate after 5 minutes, but you wanted your monitor to power down after one hour (3600 seconds) you would do this: xset dpms 3600 See the man page for the xxsseett(1) program for details. (Note that power management requires both software support in the X server, and hardware support in the monitor itself.) UUSSIINNGG XXDDMM((11)) You can run _x_s_c_r_e_e_n_s_a_v_e_r from your xxddmm(1) session, so that the screensaver will run even when nobody is logged in on the console. The trick to using xscreensaver with _x_d_m is this: keep in mind the two very different states in which xscreensaver will be running: 11:: NNoobbooddyy llooggggeedd iinn.. If you're thinking of running xscreensaver from XDM at all, then it's probably because you want graph- ics 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. 22:: SSoommeebbooddyy llooggggeedd iinn.. Once someone has logged in through the XDM login window, the situation is very different. For exam- ple: 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 _~_/_._x_s_c_r_e_e_n_- _s_a_v_e_r file; and so on. The difference between these two states comes down to a question of, which user is the _x_s_c_r_e_e_n_s_a_v_e_r process run- ning as? For the first state, it doesn't matter. If you X Version 11 20-Jun-99 (3.15) 13 XScreenSaver(1) XScreenSaver(1) start _x_s_c_r_e_e_n_s_a_v_e_r 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 _._x_s_c_r_e_e_n_s_a_v_e_r 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: 11:: LLaauunncchh xxssccrreeeennssaavveerr bbeeffoorree aannyyoonnee llooggss iinn.. To the file _/_u_s_r_/_l_i_b_/_X_1_1_/_x_d_m_/_X_s_e_t_u_p, add the lines xscreensaver-command -exit xscreensaver & 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. 22:: RReessttaarrtt xxssccrreeeennssaavveerr wwhheenn ssoommeeoonnee llooggss iinn.. Near the top of the file _/_u_s_r_/_l_i_b_/_X_1_1_/_x_d_m_/_X_s_e_s_s_i_o_n, add those same lines: xscreensaver-command -exit xscreensaver & When someone logs in, this will kill off the exist- ing (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 _~_/_._x_s_e_s_s_i_o_n files. Make sure you have $$PPAATTHH set up correctly in the _X_s_e_t_u_p and _X_s_e_s_s_i_o_n scripts, or _x_d_m won't be able to find _x_s_c_r_e_e_n_s_a_v_e_r, and/or _x_s_c_r_e_e_n_s_a_v_e_r won't be able to find its graphics demos. (If your system does not seem to be executing the _X_s_e_t_u_p X Version 11 20-Jun-99 (3.15) 14 XScreenSaver(1) XScreenSaver(1) file, you may need to configure it to do so: the tradi- tional way to do this is to make that file the value of the _D_i_s_p_l_a_y_M_a_n_a_g_e_r_*_s_e_t_u_p resource in the _/_u_s_r_/_l_i_b_/_X_1_1_/_x_d_m_/_x_d_m_-_c_o_n_f_i_g file. See the man page for xxddmm(1) for more details.) It is safe to run _x_s_c_r_e_e_n_s_a_v_e_r as root (as _x_d_m is likely to do.) If run as root, _x_s_c_r_e_e_n_s_a_v_e_r changes its effec- tive user and group ids to something safe (like _"_n_o_b_o_d_y_") before connecting to the X server or launching user-speci- fied programs. An unfortunate side effect of this (important) security precaution is that it may conflict with cookie-based authentication. If you get "connection refused" errors when running _x_s_c_r_e_e_n_s_a_v_e_r from _x_d_m, then this probably means that you have xxaauutthh(1) or some other security mechanism turned on. One way around this is to add ""xxhhoosstt ++llooccaallhhoosstt"" to _X_s_e_t_u_p, just before _x_s_c_r_e_e_n_s_a_v_e_r is launched. 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 _x_s_c_r_e_e_n_s_a_v_e_r from the _X_s_e_t_u_p 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 XX(1), XXsseeccuurriittyy(1), xxaauutthh(1), and xxhhoosstt(1). UUSSIINNGG CCDDEE ((CCOOMMMMOONN DDEESSKKTTOOPP EENNVVIIRROONNMMEENNTT)) The easiest way to use _x_s_c_r_e_e_n_s_a_v_e_r on a system with CDE is to simply switch off the built-in CDE screensaver, and use _x_s_c_r_e_e_n_s_a_v_e_r instead; and second, to tell the front panel to run xxssccrreeeennssaavveerr--ccoommmmaanndd(1) with the _-_l_o_c_k option when the _L_o_c_k icon is clicked. To accomplish this involves five steps: 11:: SSwwiittcchh ooffff CCDDEE''ss lloocckkeerr Do this by turning off ``_S_c_r_e_e_n _S_a_v_e_r _a_n_d _S_c_r_e_e_n _L_o_c_k'' in the Screen section of the Style Manager. 22:: EEddiitt sseessssiioonneettcc Edit the file _~_/_._d_t_/_s_e_s_s_i_o_n_s_/_s_e_s_s_i_o_n_e_t_c and add to it the line xscreensaver & This will cause _x_s_c_r_e_e_n_s_a_v_e_r to be launched when X Version 11 20-Jun-99 (3.15) 15 XScreenSaver(1) XScreenSaver(1) you log in. (As always, make sure that xscreen- saver and the graphics demos are on your $$PPAATTHH; the path needs to be set in _._c_s_h_r_c and/or _._d_t_p_r_o_f_i_l_e, not _._l_o_g_i_n.) 33:: CCrreeaattee XXSSccrreeeennSSaavveerr..ddtt Create a file called _~_/_._d_t_/_t_y_p_e_s_/_X_S_c_r_e_e_n_S_a_v_e_r_._d_t with the following contents: ACTION XScreenSaver { LABEL XScreenSaver TYPE COMMAND EXEC_STRING xscreensaver-command -lock ICON Dtkey WINDOW_TYPE NO_STDIO } This defines a ``lock'' command for the CDE front panel, that knows how to talk to _x_s_c_r_e_e_n_s_a_v_e_r. 44:: CCrreeaattee LLoocckk..ffpp Create a file called _~_/_._d_t_/_t_y_p_e_s_/_L_o_c_k_._f_p with the following contents: CONTROL Lock { TYPE icon CONTAINER_NAME Switch CONTAINER_TYPE SWITCH POSITION_HINTS 1 ICON Fplock LABEL Lock PUSH_ACTION XScreenSaver HELP_TOPIC FPOnItemLock HELP_VOLUME FPanel } This associates the CDE front panel ``Lock'' icon with the lock command we just defined in step 3. 55:: RReessttaarrtt Select ``_R_e_s_t_a_r_t _W_o_r_k_s_p_a_c_e _M_a_n_a_g_e_r'' from the popup menu to make your changes take effect. If things seem not to be working, check the file _~_/_._d_t_/_e_r_r_o_r_- _l_o_g for error messages. UUSSIINNGG HHPP VVUUEE ((VVIISSUUAALL UUSSEERR EENNVVIIRROONNMMEENNTT)) Since CDE is a descendant of VUE, the instructions for using xscreensaver under VUE are similar to the above: 11:: SSwwiittcchh ooffff VVUUEE''ss lloocckkeerr Open the ``_S_t_y_l_e _M_a_n_a_g_e_r'' and select ``_S_c_r_e_e_n.'' Turn off ``_S_c_r_e_e_n _S_a_v_e_r _a_n_d _S_c_r_e_e_n _L_o_c_k'' option. X Version 11 20-Jun-99 (3.15) 16 XScreenSaver(1) XScreenSaver(1) 22:: MMaakkee ssuurree yyoouu hhaavvee aa SSeessssiioonn Next, go to the Style Manager's, ``_S_t_a_r_t_u_p'' page. Click on ``_S_e_t _H_o_m_e _S_e_s_s_i_o_n'' to create a session, then on ``_R_e_t_u_r_n _t_o _H_o_m_e _S_e_s_s_i_o_n'' to select this session each time you log in. 33:: EEddiitt vvuuee..sseessssiioonn Edit the file _~_/_._v_u_e_/_s_e_s_s_i_o_n_s_/_h_o_m_e_/_v_u_e_._s_e_s_s_i_o_n and add to it the line vuesmcmd -screen 0 -cmd "xscreensaver" This will cause _x_s_c_r_e_e_n_s_a_v_e_r to be launched when you log in. (As always, make sure that xscreen- saver and the graphics demos are on your $$PPAATTHH; the path needs to be set in _._c_s_h_r_c and/or _._p_r_o_f_i_l_e, not _._l_o_g_i_n.) 33:: EEddiitt vvuueewwmmrrcc Edit the file _~_/_._v_u_e_/_v_u_e_w_m_r_c and add (or change) the Lock control: CONTROL Lock { TYPE button IMAGE lock PUSH_ACTION f.exec "xscreensaver-command -lock" HELP_TOPIC FPLock } This associates the VUE front panel ``Lock'' icon with the xscreensaver lock command. AADDDDIINNGG TTOO MMEENNUUSS The xxssccrreeeennssaavveerr--ccoommmmaanndd(1) program is a perfect candidate for something to add to your window manager's popup menus. If you use mmwwmm(1), 44DDwwmm(1), ttwwmm(1), or (probably) any of _t_w_m's many descendants, you can do it like this: 11.. CCrreeaattee ~~//..mmwwmmrrcc ((oorr ~~//..ttwwmmrrcc oorr ......)) If you don't have a _~_/_._m_w_m_r_c file (or, on SGIs, a _~_/_._4_D_w_m_r_c file; or, with twm, a _~_/_._t_w_m_r_c file) then create one by making a copy of the _/_u_s_r_/_l_i_b_/_X_1_1_/_s_y_s_- _t_e_m_._m_w_m_r_c file (or _/_u_s_r_/_l_i_b_/_X_1_1_/_t_w_m_/_s_y_s_t_e_m_._t_w_m_r_c, and so on.) 22.. AAdddd aa mmeennuu ddeeffiinniittiioonn.. Something like this: menu XScreenSaver { "Blank Screen Now" !"sleep 3; xscreensaver-command -activate" "Lock Screen Now" !"sleep 3; xscreensaver-command -lock" X Version 11 20-Jun-99 (3.15) 17 XScreenSaver(1) XScreenSaver(1) "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 &" } 33.. AAdddd tthhee mmeennuu For mmwwmm(1) and 44DDwwmm(1), find the section of the file that says _M_e_n_u _D_e_f_a_u_l_t_R_o_o_t_M_e_n_u. For ttwwmm(1), it will probably be _m_e_n_u _"_d_e_f_o_p_s_". If you add a line somewhere in that menu definition that reads "XScreenSaver" f.menu XScreenSaver then this will add an XScreenSaver sub-menu to your default root-window popup menu. Alternately, you could just put the xscreensaver menu items directly into the root menu. Other window managers are guaranteed to do things gratu- itously differently. BBUUGGSS Bugs? There are no bugs. Ok, well, maybe. If you find one, please let me know. http://www.jwz.org/xscreen- saver/bugs.html explains how to construct the most useful bug reports. LLoocckkiinngg aanndd XXDDMM If xscreensaver has been launched from xxddmm(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 _~_/_._x_s_c_r_e_e_n_s_a_v_e_r file will be ignored.) When you are logged in, you want the _x_s_c_r_e_e_n_s_a_v_e_r daemon to be running under _y_o_u_r user id, not as root or some other user. If it has already been started by _x_d_m, you can kill it by sending it the eexxiitt command, and then re-launching it as you, by putting something like the following in your personal X startup script: xscreensaver-command -exit xscreensaver & The ``_U_s_i_n_g _X_D_M_(_1_)'' section, above, goes into more detail, and explains how to configure the system to do this for all users automatically. X Version 11 20-Jun-99 (3.15) 18 XScreenSaver(1) XScreenSaver(1) LLoocckkiinngg aanndd rroooott llooggiinnss In order for it to be safe for xscreensaver to be launched by _x_d_m, certain precautions had to be taken, among them that xscreensaver never runs as _r_o_o_t. In particular, if it is launched as root (as _x_d_m is likely to do), xscreensaver will dis- avow its privileges, and switch itself to a safe user id (such as _n_o_b_o_d_y.) An implication of this is that if you log in as _r_o_o_t on the console, xscreensaver will refuse to lock the screen (because it can't tell the differ- ence between _r_o_o_t being logged in on the console, and a normal user being logged in on the console but xscreensaver having been launched by the xxddmm(1) _X_s_e_t_u_p file.) The solution to this is simple: you shouldn't be logging in on the console as _r_o_o_t in the first place! (What, are you crazy or something?) Proper Unix hygiene dictates that you should log in as yourself, and ssuu(1) to _r_o_o_t as necessary. People who spend their day logged in as _r_o_o_t are just begging for disaster. XXAAUUTTHH aanndd XXDDMM For xscreensaver to work when launched by xxddmm(1), programs running on the local machine as user _"_n_o_b_o_d_y_" 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 ``_U_s_i_n_g _X_D_M_(_1_)'' section, above, for more details. If anyone has suggestions on how xscreensaver could be made to work with xxddmm(1) without first turning off _._X_a_u_t_h_o_r_i_t_y-based access control, please let me know. PPaasssswwoorrddss If you get an error message at startup like ``couldn't get password of _u_s_e_r'' then this proba- bly means that you're on a system in which the ggeettppwweenntt(3) library routine can only be effec- tively used by root. If this is the case, then _x_s_c_r_e_e_n_s_a_v_e_r must be installed as setuid to root in order for locking to work. Care has been taken X Version 11 20-Jun-99 (3.15) 19 XScreenSaver(1) XScreenSaver(1) to make this a safe thing to do. It also may mean that your system uses shadow passwords instead of the standard ggeettppwweenntt(3) interface; in that case, you may need to change some options with _c_o_n_f_i_g_u_r_e 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. So, after you change your password, you'll have to do xscreensaver-command -restart to make _x_s_c_r_e_e_n_s_a_v_e_r notice. PPAAMM PPaasssswwoorrddss 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 _/_e_t_c_/_p_a_m_._d_/_x_s_c_r_e_e_n_s_a_v_e_r for you, and on Solaris, by telling you what lines to add to the _/_e_t_c_/_p_a_m_._c_o_n_f file.) If the PAM configuration files do not know about xscreensaver, then you _m_i_g_h_t 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 xscreen- saver to automatically work around this, or detect the problem in advance, so if you have PAM, make sure it is configured correctly! CCoolloorrmmaapp lloossssaaggee:: TTWWMM The iinnssttaallllCCoolloorrmmaapp option doesn't work very well with the ttwwmm(1) window manager and its descen- dants. There is a race condition between the screensaver and this window manager, which can result in the screensaver's colormap not getting installed prop- erly, meaning the graphics hacks will appear in essentially random colors. (If the screen goes white instead of black, this is probably why.) The mmwwmm(1) and oollwwmm(1) window managers don't have X Version 11 20-Jun-99 (3.15) 20 XScreenSaver(1) XScreenSaver(1) 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, ttwwmm responds to the resultant CCoolloorrmmaappNNoottiiffyy event by re- instaling the default colormap. Apparently, ttwwmm doesn't _a_l_w_a_y_s do this; it seems to do it regu- larly 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. AAtttteennttiioonn,, wwiinnddooww mmaannaaggeerr aauutthhoorrss!! You should only call XXIInnssttaallllCCoolloorrmmaapp(3) in response to user events. That is, it is appropriate to install a colormap in response to FFooccuussIInn, FFooccuussOOuutt, EEnntteerrNNoottiiffyy, and LLeeaavveeNNoottiiffyy events; but it is not appropriate to call it in response to CCoolloorrmmaappNNoottiiffyy events. If you install colormaps in response to _a_p_p_l_i_c_a_t_i_o_n actions as well as in response to _u_s_e_r 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. CCoolloorrmmaapp lloossssaaggee:: XXVV,, XXAAnniimm,, XXEEaarrtthh Some programs don't operate properly on visuals other than the default one, or with colormaps other than the default one. See the discussion of the magic "default-n" visual name in the descrip- tion of the pprrooggrraammss resource in the _C_o_n_f_i_g_u_r_a_t_i_o_n section. When programs only work with the default colormap, you need to use a syntax like this: default-n: xv -root image-1.gif -quit \n\ default-n: xearth -nostars -wait 0 \n\ It would also work to turn off the iinnssttaallllCCoolloorrmmaapp option altogether, but that would deny extra col- ors to those programs that _c_a_n take advantage of them. MMaacchhiinnee LLooaadd 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 sslleeeepp(3) or uusslleeeepp(3) X Version 11 20-Jun-99 (3.15) 21 XScreenSaver(1) XScreenSaver(1) (or making liberal use of any _-_d_e_l_a_y 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 xxcclloocckk(1) or xxllooaadd(1). LLaatteennccyy aanndd RReessppoonnssiivveenneessss 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 iiccoo(1) demo has this problem if being run in full-speed mode). This can be alleviated by inserting strategic calls to XXSSyynncc(3) in code intended for use as a screensaver. This prevents too much graphics activity from being buffered up. XXFFrreeee8866''ss MMaaggiicc KKeeyyssttrrookkeess 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_n, which switches virtual consoles. The X server will respond to these keystrokes even if xscreen- saver 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 _D_o_n_t_Z_a_p flag in your _/_e_t_c_/_X_1_1_/_X_F_8_6_C_o_n_f_i_g file. See the XXFF8866CCoonnffiigg(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 prob- lem are welcome. X Version 11 20-Jun-99 (3.15) 22 XScreenSaver(1) XScreenSaver(1) XXVViieeww CClliieennttss Apparently there are some problems with XView pro- grams getting confused and thinking that the screensaver window is the real root window even when the screensaver is not active: ClientMessages intended for the window manager are sent to the screensaver window instead. This could be solved by making xscreensaver forward all unrecognised ClientMessages to the real root window, but there may be other problems as well. If anyone has any insight on the cause of this problem, please let me know. (XView is an X11 toolkit that implements the (quite abominable) Sun OpenLook look-and- feel.) MMIITT EExxtteennssiioonn aanndd FFaaddiinngg The MMIITT--SSCCRREEEENN--SSAAVVEERR extension is junk. Don't use it. When using the MMIITT--SSCCRREEEENN--SSAAVVEERR extension in con- junction with the ffaaddee 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 _x_s_c_r_e_e_n_s_a_v_e_r process to activate. The _x_s_c_r_e_e_n_s_a_v_e_r process immediately unmaps that window, but this results in a flicker. I haven't figured a way to get around this; it seems to be a fundamental property of the (mis-) design of this server extension. It sure would be nice if someone would implement the SSGGII SSCCRREEEENN__SSAAVVEERR extension in XFree86; it's dead simple, and works far better than the overengineered and broken MMIITT--SSCCRREEEENN--SSAAVVEERR exten- sion. SSGGII PPoowweerr SSaavveerr If you're running Irix 6.3, you might find that your monitor is powering down after an hour or two even if you've told it not to. This is fixed by SGI patches 2447 and 2537. If you're running Irix 6.5, this bug is back. I don't know a fix. MMeessaaGGLL aanndd VVooooddoooo CCaarrddss If you have a 3Dfx/Voodoo card, the default set- tings 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 pprrooggrraammss entries for X Version 11 20-Jun-99 (3.15) 23 XScreenSaver(1) XScreenSaver(1) the GL hacks from this: gears -root \n\ to this: MESA_GLX_FX=fullscreen gears \n\ That is, make sure that $$MMEESSAA__GGLLXX__FFXX is set to _f_u_l_l_s_c_r_e_e_n, 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 _i_s strange! For those who don't know, these cards work by sit- ting between your normal video card and the moni- tor, 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 _/_d_e_v_/_3_d_f_x file is not configured properly. Check the Linux 3Dfx FAQ. KKeeyybbooaarrdd LLEEDDss If _p_r_o_c_I_n_t_e_r_r_u_p_t_s is on (which is the default on Linux systems) and you're using some program that toggles the state of your keyboard LEDs, xscreen- saver won't work right: turning those LEDs on or off causes a keyboard interrupt, which xscreen- saver will interpret as user activity. So if you're using such a program, set the _p_r_o_c_I_n_t_e_r_- _r_u_p_t_s resource to False. EExxtteennssiioonnss If you are not making use of one of the server extensions (XXIIDDLLEE, SSGGII SSCCRREEEENN__SSAAVVEERR, or MMIITT-- SSCCRREEEENN--SSAAVVEERR), then it is possible, in rare situa- tions, for _x_s_c_r_e_e_n_s_a_v_e_r to interfere with event propagation and make another X program malfunc- tion. For this to occur, that other application would need to _n_o_t select KKeeyyPPrreessss 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 _m_i_g_h_t fail to receive those events. This isn't very likely, since pro- grams generally select a constant set of events immediately after creating their windows and then don't change them, but this is the reason that X Version 11 20-Jun-99 (3.15) 24 XScreenSaver(1) XScreenSaver(1) 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 sin- gle case of this happening, but it is theoreti- cally possible, so I'm mentioning it for complete- ness... RReedd HHoott LLaavvaa There need to be a lot more graphics hacks. In particular, there should be a simulation of a Lavalite (tm). EENNVVIIRROONNMMEENNTT DDIISSPPLLAAYY to get the default host and display number, and to inform the sub-programs of the screen on which to draw. PPAATTHH to find the sub-programs to run. HHOOMMEE for the directory in which to read and write the _._x_s_c_r_e_e_n_s_a_v_e_r file. XXEENNVVIIRROONNMMEENNTT to get the name of a resource file that overrides the global resources stored in the RESOURCE_MAN- AGER property. UUPPGGRRAADDEESS The latest version can always be found at http://www.jwz.org/xscreensaver/ SSEEEE AALLSSOO XX(1), xxssccrreeeennssaavveerr--ddeemmoo(1), xxssccrreeeennssaavveerr--ccoommmmaanndd(1), xxddmm(1), xxsseett(1), XXsseeccuurriittyy(1), xxaauutthh(1), xxhhoosstt(1). aanntt(1), aattllaannttiiss(1), aattttrraaccttiioonn(1), bblliittssppiinn(1), bboouubboouullee(1), bbrraaiidd(1), bbssoodd(1), bbuubbbbllee33dd(1), bbuubbbblleess(1), ccaaggee(1), ccoommppaassss(1), ccoorraall(1), ccrriittiiccaall(1), ccrryyssttaall(1), ccyynnoossuurree(1), ddeeccaayyssccrreeeenn(1), ddeeccoo(1), ddeelluuxxee(1), ddeemmoonn(1), ddiissccrreettee(1), ddiissttoorrtt(1), ddrriifftt(1), eeppiiccyyccllee(1), ffaaddee-- pplloott(1), ffllaagg(1), ffllaammee(1), ffllooww(1), ffoorreesstt(1), ggaallaaxxyy(1), ggeeaarrss(1), ggllppllaanneett(1), ggoooopp(1), ggrraavv(1), ggrreeyynneettiicc(1), hhaalloo(1), hheelliixx(1), hhooppaalloonngg(1), hhyyppeerrccuubbee(1), iiffss(1), iimmssmmaapp(1), iinntteerrffeerreennccee(1), jjiiggssaaww(1), jjuulliiaa(1), kkaalleeii-- ddeessccooppee(1), kkuummppppaa(1), llaammeenntt(1), llaasseerr(1), lliigghhttnniinngg(1), lliissaa(1), lliissssiiee(1), llmmoorrpphh(1), lloooopp(1), mmaazzee(1), mmooee-- bbiiuuss(1), mmooiirree(1), mmooiirree22(1), mmoorrpphh33dd(1), mmoouunnttaaiinn(1), mmuunncchh(1), nnoosseegguuyy(1), ppeeddaall(1), ppeenneettrraattee(1), ppeennrroossee(1), ppeettrrii(1), pphhoosspphhoorr(1), ppiippeess(1), ppuullssaarr(1), ppyyrroo(1), qqiixx(1), rrdd--bboommbb(1), rroocckkss(1), rroorrsscchhaacchh(1), rroottoorr(1), rruubbiikk(1), ssiieerrppiinnsskkii(1), sslliiddeessccrreeeenn(1), sslliipp(1), ssoonnaarr(1), sspphheerree(1), ssppiirraall(1), ssppoottlliigghhtt(1), sspprrooiinn-- ggiieess(1), ssqquuiirraall(1), ssttaaiirrss(1), ssttaarrffiisshh(1), ssttrraannggee(1), X Version 11 20-Jun-99 (3.15) 25 XScreenSaver(1) XScreenSaver(1) ssuuppeerrqquuaaddrriiccss(1), sswwiirrll(1), tt33dd(1), ttrriiaannggllee(1), ttrruucchheett(1), vviinneess(1), wwaannddeerr(1), wwoorrmm(1), xxffllaammee(1), xxjjaacckk(1), xxllyyaapp(1), xxmmaattrriixx(1), xxrrooggeerr(1), bboonnggoo(1), iiccoo(1), xxaaooss(1), xxbboouunncceebbiittss(1), xxcctthhuugghhaa(1), xxddaallii-- cclloocckk(1), xxffiisshhttaannkk(1), xxmmoouunnttaaiinnss(1), xxsspplliinneeffuunn(1), xxsswwaarrmm(1), xxttaaccyy(1), xxvv(1), xxwwaavvee(1). CCOOPPYYRRIIGGHHTT Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999 by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell this software and its docu- mentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this per- mission notice appear in supporting documentation. No representations are made about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. AAUUTTHHOORR Jamie Zawinski . Written in late 1991; first posted to comp.sources.x on 13-Aug-1992. Please let me know if you find any bugs or make any improvements. AACCKKNNOOWWLLEEDDGGEEMMEENNTTSS Thanks to the many people who have contributed graphics demos to the package. Thanks to David Wojtowicz for implementing _l_o_c_k_T_i_m_e_o_u_t. Thanks to Martin Kraemer for adding support for shadow passwords and locking-disabled diagnostics. Thanks to Patrick Moreau for the VMS port. Thanks to Mark Bowyer for figuring out how to hook it up to CDE. Thanks to Nat Lanza for the Kerberos support. Thanks to Bill Nottingham for the initial PAM support. And thanks to Jon A. Christopher for implementing the Athena dialog support, back in the days before Lesstif or Gtk were viable alternatives to Motif. X Version 11 20-Jun-99 (3.15) 26