== xss ==

`xss` uses the nearly 20-year-old MIT-SCREEN-SAVER extension to launch a
program when the X server turns on the built-in screen saver.

`xsswin` makes a full-screen black window and runs some other program,
passing along the window ID in the environment ($XSS_WINDOW) and
possibly as an argument (XSS_WINDOW gets replaced with the id).  It does
not grab keyboard or mouse focus: you'll have to run something else
(like `xtrlock`) to do this or other windows will continue to get
keyboard and mouse events.

`xcursorpos` prints out the x and y coordinates of the cursor.

Examples
--------

Tell the X server to launch the screen saver after 90 seconds idle:

    xset s 90


Run like `xautolock`:

    xss xlock -mode qix &


Shell script to run an `xscreensaver` hack and `xtrlock` at the same
time, but prevent locking if the cursor is in the upper-left corner:

    #! /bin/sh
    
    xcursorpos | (read x y; [ $x -lt 20 -a $y -lt 20 ]) && exit 0
    xsswin /usr/lib/xscreensaver/qix -window-id XSS_WINDOW &
    pid=$!
    xtrlock
    kill $pid


History
-------

AIX apparently had something also called `xss` which did almost exactly
what mine does, but with command-line options.

I'm not aware of anything else like `xsswin` or `xcursorpos`.  If there
is already something out there to do these jobs please let me know so I
can quit using my versions.

I lifted some code from `beforelight` from the X11 distribution, and
from `slock` from [suckless.org](http://suckless.org/).  Both have a
BSD/X11-like license.


------

Neale Pickett <neale@woozle.org>