XLOCK(1) USER COMMANDS XLOCK(1)
NAME
xlock - Locks the local X display till a password is
entered.
SYNOPSIS
xlock [ -display dsp ] [ -mode mode ] [ -time timeout ] [
-count n ] [ -nice nicelevel ] [ -font fontname ] [ -color ]
[ -lock ] [ -root ] [ -xhost ] [ -screensaver ] [ -echokeys
] [ -v ] [ -install ]
DESCRIPTION
xlock locks the X server till the user enters their password
at the keyboard. While xlock is running, all new server
connections are refused. The screen saver is disabled. The
mouse cursor is turned off. The screen is blanked and a
changing pattern is put on the screen. The pattern changes
after timeout seconds. If a key or a mouse button is pressed
then the user is prompted for the password of the user who
started xlock.
If the correct password is typed, then the screen is
unlocked and the X server is restored. When typing the
password Control-U and Control-H are active as kill and
erase respectively. To return to the locked screen, click
in the small icon version of the changing pattern.
OPTIONS
-display dsp
The display option sets the X11 display to lock. xlock
follows standard X11 naming convention for displays as
in machinename:server.screen, if you are only display-
ing the lockscreen animation, (see -lock ), but will
not allow one to lock another server's display thus
only unix:server.screen, localhost:server.screen, and
:server.screen are allowed for dsp. Where server is
which X11 server socket to connect to and screen is
which head to display the pattern on.
-mode modename
As of this writing there are three display modes sup-
ported.
hop Hop mode shows the "real plane fractals" from the
September 1986 issue of Scientific American.
life Life mode shows Conway's game of life.
qix Qix mode shows the spinning lines similar to the old
video game by the same name.
OpenWindows 1.1Beta1Last change: 18 Feb 1990 1
XLOCK(1) USER COMMANDS XLOCK(1)
-time timeout
The time option sets the number of seconds that each
unique fractal will remain on the screen before being
replaced by the next one to timeout.
-count n
The count option sets the speed at which a mode will
operate. The different modes interpret this value dif-
ferently. For 'hop' and 'qix' this sets the number of
pixels and lines respectively to draw in each color.
These patterns are calculated in batches of n objects,
then sent to the server in a single color. Faster
machines, expecially machines with floating point
hardware can set this to a higher number and still have
fast changing patterns. The 'life' mode, in contrast
interprets this number as the number of milliseconds to
delay after each generation of the "critters". A low
number here makes the pattern change rapidly, where
1000 means wait a second between generations.
-font fontname
The font option sets the font to be used on the prompt
screen.
-nice nicelevel
The nice option sets system nicelevel of the xlock pro-
cess to nicelevel .
-color
The color option causes xlock to display monochrome,
(black and white) pixels rather than the default
colored ones on color displays.
-lock
The lock option causes xlock to only draw the patterns
and not lock the display. A keypress or a mouse click
will terminate the screen saver.
-root
The root option allows the root password to unlock the
server as well as the user who started xlock.
-xhost
This option is simply a hack for the paranoid, who
don't want to disable the access control list, but
still want the local server to prompt for a password.
This way if xlock is killed -KILL, the access control
list is not lost.
-screensaver
By default xlock will disable the normal X server's
screen saver since it is in effect a replacement for
OpenWindows 1.1Beta1Last change: 18 Feb 1990 2
XLOCK(1) USER COMMANDS XLOCK(1)
it. Since it is possible to set delay parameters long
enough to cause phosphor burn on some displays, this
option will turn back on the default screensaver which
is very careful to keep most of the screen black.
-echokeys
The echokeys option causes xlock to echo '?' characters
for each key typed into the password prompt. Some con-
sider this a security risk, so the default is to not
echo anything.
-v Verbose mode, tells what options it is going to use.
-install
Forcibly install the colormap. This violates ICCCM
standards and will not work with ICCCM compliant window
managers. This option exists for backward compatibil-
ity with older versions of xlock.
BUGS
"kill -KILL xlock " causes server to be unusable, since
xlock has removed all hosts (including localhost) from the
access control list to lock out all new X clients, and SIG-
KILL cannot be caught by any program, xlock will terminate
before restoring the access control list. This will leave
the X server in a state where
"you can no longer connect to that server, and this opera-
tion cannot be reversed short of resetting the server."
-From the X11R2 Xlib Documentation page 140.
SEE ALSO
X(1), Xlib Documentation.
AUTHOR
Patrick J. Naughton (naughton@sun.com)
Window Systems Group
Sun Microsystems, Inc.
Mountain View, CA 94043
415/336-1080
COPYRIGHT
Copyright (c) 1988-90 by Patrick J. Naughton and Sun
Microsystems, Inc.
Permission to use, copy, modify, and distribute this
software and its documentation for any purpose and without
fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
OpenWindows 1.1Beta1Last change: 18 Feb 1990 3
XLOCK(1) USER COMMANDS XLOCK(1)
documentation.
CONTRIBUTORS
milliken@heron.bbn.com karlton@wsl.dec.com
dana@thumper.bellcore.com vesper@3d.dec.com flar@sun.com
OpenWindows 1.1Beta1Last change: 18 Feb 1990 4