A customizable slackware theme for the XDM login manager.

By default the image C2-Ocean-Side-Sunset-2.jpg is defined as the XDM 
background image source. This can be changed by passing XDMBGIMG=<img> 
on the command line, <img> can be one of the following :

  C1-Nights-Haze-Blue-2.jpg         C2-Green-Moutain-Side-2.jpg
  C1-Nights-Haze-Grey-2.jpg         C2-Morning-View-2.jpg
  C1-Nights-Haze-Purple-2.jpg       C2-Ocean-Side-Sunset-2.jpg
  C1-Shuttleworth-Galaxy-2.jpg      C2-Precipice.jpg
  C1-Steele-Star-2.jpg              C2-Sunset-Shore-2.jpg
                                    C2-The-Rivers-Of-Cuomo-2.jpg

  Geminid-Meteor-Shower.jpg         Green-Hills.jpg
  Mars-Olympus-Mons.jpg             Space-Outer-Nature.jpg

Example:

 $ XDMBGIMG=Green-Hills.jpg ./xdm-slackware-theme.SlackBuild

xdm-slackware-theme optionally requires:

 numlockx (https://slackbuilds.org/repository/14.2/system/numlockx/)
 compton (https://slackbuilds.org/repository/14.2/desktop/compton/)
 feh (https://slackbuilds.org/repository/14.2/graphics/feh/)
 xonclock (https://slackbuilds.org/repository/14.2/desktop/xonclock/)
 cairo-clock (https://slackbuilds.org/repository/14.2/desktop/cairo-clock/)
 conky (https://slackbuilds.org/repository/14.2/system/conky/)

Attention, when xdm-slackware-theme is configured with compton support
while feh is not installed, compton support is automatically disabled
because compton is incompatible with imagemagick's display command
(used by xdm-slackware-theme when feh is not available).

Full documentation is available at:
https://xdm-slackware-theme.sourceforge.io/