NAME

xlock − Locks the local X display till a password is entered. 
 

SYNOPSIS

xlock [ −display dsp ] [ −mode mode ] [ −time timeout ] [ −count iterations ] [ −font  fontname ] [ −mono ] [ −saver ] [ −root ] [ −v ]
 

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, characters are not echoed to the screen, but 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 will not allow one to lock another server’s displays 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 supported.

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. 

−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  iterations
The count option sets the number of iterations to draw in each color.  The patterns are calculated in batches of iterations 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. 

−font  fontname
The font option sets the font to be used on the prompt screen. 

−mono
The mono option causes xlock to display monochrome, (black and white) pixels rather than the default colored ones. 

−saver
The saver option causes xlock to only draw the fractals 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. 

−v Verbose mode, tells what options it is going to use. 
 

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 SIGKILL 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 operation 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@wind.sun.com)
 Window Systems Group
 Sun Microsystems, Inc.
 Mountain View, CA  94043
 415/336-1080
 

COPYRIGHT

Copyright (c) 1989 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 documentation.
 

CONTRIBUTORS

  milliken@heron.bbn.comkarlton@wsl.dec.com
  dana@thumper.bellcore.comvesper@3d.dec.com

X11/NeWS 1.0  —  Last change: 01 Jun 1989