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-.TH XScreenSaver 1 "08-Oct-98 (2.34)" "X Version 11"
+.TH XScreenSaver 1 "14-Aug-2004 (4.18)" "X Version 11"
.SH NAME
xscreensaver-command - control a running xscreensaver process
.SH SYNOPSIS
.B xscreensaver-command
-[\-help] \
-[\-demo] \
-[\-prefs] \
-[\-activate] \
-[\-deactivate] \
-[\-cycle] \
-[\-next] \
-[\-prev] \
-[\-select \fIn\fP] \
-[\-exit] \
-[\-restart] \
-[\-lock] \
-[\-version] \
-[\-time]
+[\-display \fIhost:display.screen\fP] \
+[\-help | \
+\-demo | \
+\-prefs | \
+\-activate | \
+\-deactivate | \
+\-cycle | \
+\-next | \
+\-prev | \
+\-select \fIn\fP | \
+\-exit | \
+\-restart | \
+\-lock | \
+\-throttle | \
+\-unthrottle | \
+\-version | \
+\-time | \
+\-watch]
.SH DESCRIPTION
The \fIxscreensaver\-command\fP program controls a running \fIxscreensaver\fP
process by sending it client-messages.
.BR xscreensaver (1)
has a client-server model: the xscreensaver process is a
-daemon that runs in the background; it is controlled by the
-foreground \fIxscreensaver-command\fP program.
+daemon that runs in the background; it is controlled by other
+foreground programs such as \fIxscreensaver-command\fP and
+.BR xscreensaver\-demo (1).
+
+This program, \fIxscreensaver-command\fP, is a command-line-oriented tool; the
+.BR xscreensaver\-demo (1).
+program is a graphical tool.
.SH OPTIONS
.I xscreensaver-command
accepts the following command-line options:
Prints a brief summary of command-line options.
.TP 8
.B \-demo
-Cause the screensaver to enter its interactive demo mode, in which one
-can experiment with the various graphics hacks available. See
+This just launches the
+.BR xscreensaver\-demo (1)
+program, in which one can experiment with the various graphics hacks
+available, and edit parameters.
+.TP 8
+.B \-demo \fP\fInumber\fP
+When the \fI\-demo\fP option is followed by an integer, it instructs
+the \fIxscreensaver\fP daemon to run that hack, and wait for the user
+to click the mouse before deactivating (i.e., mouse motion does not
+deactivate.) This is the mechanism by which
+.BR xscreensaver\-demo (1)
+communicates with the
.BR xscreensaver (1)
-for details.
+daemon. (The first hack in the list is numbered 1, not 0.)
.TP 8
.B \-prefs
-Cause the screensaver to enter its interactive demo mode, and bring up
-the Preferences control panel, in which one can change most of the settings
-that control the xscreensaver daemon's behavior. See
-.BR xscreensaver (1)
-for details.
+Like the no-argument form of \fI\-demo\fP, but brings up that program's
+Preferences panel by default.
.TP 8
.B \-activate
Tell xscreensaver to turn on immediately (that is, blank the screen, as if
.EX
sleep 5 ; xscreensaver-command -activate
.EE
-to be sure that you have time to remove your hand from the mouse before
+to be sure that you have time to take your hand off the mouse before
the screensaver comes on. (Because if you jiggle the mouse, xscreensaver
will notice, and deactivate.)
.TP 8
.B \-deactivate
-If the screensaver is active (the screen is blanked), this command will
-deactivate it just as if there had been keyboard or mouse activity.
-If locking is enabled, then the screensaver will prompt for a password
-as usual.
+This tells xscreensaver to pretend that there has just been user activity.
+This means that if the screensaver is active (the screen is blanked),
+then this command will cause the screen to un-blank as if there had been
+keyboard or mouse activity. If the screen is locked, then the password
+dialog will pop up first, as usual. If the screen is not blanked, then
+this simulated user activity will re-start the countdown (so, issuing
+the \fI\-deactivate\fP command periodically is \fIone\fP way to prevent
+the screen from blanking.)
.TP 8
.B \-cycle
If the screensaver is active (the screen is blanked), then stop the current
things in an inconsistent state, and you may need to restart your window
manager to repair the damage.
.TP 8
-.B \-restart
-Causes the screensaver process to exit and then restart with the same command
-line arguments as last time. Do this after you've changed the resource
-database, to cause xscreensaver to notice the changes.
-
-If the screensaver is run from \fIxdm(1)\fP (that is, it is already running
-before you log in) then you may want to issue the \fI\-restart\fP command from
-one of your startup scripts, so that the screensaver gets your resource
-settings instead of the default ones.
-.TP 8
.B \-lock
Tells the running xscreensaver process to lock the screen immediately.
This is like \fI\-activate\fP, but forces locking as well, even if locking
is not the default (that is, even if xscreensaver's \fIlock\fP resource is
false, and even if the \fIlockTimeout\fP resource is non-zero.)
+
+Note that locking doesn't work unless the \fIxscreensaver\fP process is
+running as you. See
+.BR xscreensaver (1)
+for details.
+.TP 8
+.B \-throttle
+Temporarily switch to ``blank screen'' mode, and don't run any display modes
+at all, until the screensaver is next de-activated. This is useful if you're
+using a machine remotely, and you find that some display modes are using too
+much CPU.
+
+(If you want to do this \fIpermanently\fP, that is, you want the screen saver
+to only blank the screen and not run demos at all, then set the \fImode\fP
+preference to "blank": See
+.BR xscreensaver (1)
+for details.)
+.TP 8
+.B \-unthrottle
+Turn `-throttle' mode off and resume normal behavior.
.TP 8
.B \-version
Prints the version of xscreensaver that is currently running on the display:
deactivated (roughly, how long the user has been idle or non-idle: but
not quite, since it only tells you when the screen became blanked or
un-blanked.)
+.TP 8
+.B \-restart
+Causes the screensaver process to exit and then restart with the same command
+line arguments as last time. Do this after you've changed the resource
+database, to cause xscreensaver to notice the changes.
+
+.B Warning:
+if you have a \fI.xscreensaver\fP file, this might not do what you
+expect. You're probably better off killing the existing
+xscreensaver (with \fIxscreensaver\-command -exit\fP) and then
+launching it again.
+
+The important point is, you need to make sure that the xscreensaver
+process is running as you. If it's not, it won't be reading the
+right \fI.xscreensaver\fP file.
+.TP 8
+.B \-watch
+Prints a line each time the screensaver changes state: when the screen
+blanks, locks, unblanks, or when the running hack is changed. This option
+never returns; it is intended for use by shell scripts that want to react to
+the screensaver in some way. An example of its output would be:
+.EX
+BLANK Fri Nov 5 01:57:22 1999
+RUN 34
+RUN 79
+RUN 16
+LOCK Fri Nov 5 01:57:22 1999
+RUN 76
+RUN 12
+UNBLANK Fri Nov 5 02:05:59 1999
+.EE
+The above shows the screensaver activating, running three different
+hacks, then locking (perhaps because the lock-timeout went off) then
+unblanking (because the user became active, and typed the correct
+password.) The hack numbers are their index in the `programs'
+list (starting with 1, not 0, as for the \fI\-select\fP command.)
+
+For example, suppose you want to run a program that turns down the volume
+on your machine when the screen blanks, and turns it back up when the screen
+un-blanks. You could do that by running a Perl program like the following
+in the background. The following program tracks the output of
+the \fI\-watch\fP command and reacts accordingly:
+.EX
+#!/usr/bin/perl
+
+my $blanked = 0;
+open (IN, "xscreensaver-command -watch |");
+while (<IN>) {
+ if (m/^(BLANK|LOCK)/) {
+ if (!$blanked) {
+ system "sound-off";
+ $blanked = 1;
+ }
+ } elsif (m/^UNBLANK/) {
+ system "sound-on";
+ $blanked = 0;
+ }
+}
+.EE
+Note that LOCK might come either with or without a preceeding BLANK
+(depending on whether the lock-timeout is non-zero), so the above program
+keeps track of both of them.
.SH DIAGNOSTICS
If an error occurs while communicating with the \fIxscreensaver\fP daemon, or
if the daemon reports an error, a diagnostic message will be printed to
.SH UPGRADES
The latest version of
.BR xscreensaver (1)
-and \fIxscreensaver\-command\fP can always be found at
-http://www.jwz.org/xscreensaver/
+and related tools can always be found at http://www.jwz.org/xscreensaver/
.SH "SEE ALSO"
.BR X (1),
.BR xscreensaver (1)
+.BR xscreensaver\-demo (1)
.SH COPYRIGHT
-Copyright \(co 1992, 1993, 1997, 1998
+Copyright \(co 1992, 1993, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell
this software and its documentation for any purpose is hereby granted without
fee, provided that the above copyright notice appear in all copies and that
projects / xscreensaver / blobdiff