.if n .sp 1
.if t .sp .5
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-.TH XScreenSaver 1 "15-Nov-98 (3.03)" "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.
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
.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:
that is, the actual version number of the running xscreensaver background
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
.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