Google is always helpful of course, so I've found this blog entry on how to set the background in xfce.

It boils down to setting a jpg in XFCE's backdrops.list and then reloading xfdesktop. Crude, but it works.

This can de done with the following command:

cat <<EOF > ~/.config/xfce4/desktop/backdrops.list
# xfce backdrop list
background.jpg
EOF

And then

xfdesktop --reload

However when running from CRON it is more easy to do a killall -USR1 xfdesktop.

A collage from ATComputing, Jacques loonen had a little script that will download a nice image from some site showing the earth with actual clouds rendered on it. I'm going to use it to make a background that slowly changes from day into night and vice verse.

The following script wil be run from cron, it will generate a new jpg suitable for background use. Images from opentopia.com are particularly nice.

#!/bin/sh
IMG=/home/miekg/tmp/xfce_bg.jpg
wget \
http://www.opentopia.com/images/cams/world_sunlight_map_hemisphere.jpg \
-O $IMG 
# not really needed, but... heh
cat <<EOF > ~/.config/xfce4/desktop/backdrops.list
# xfce backdrop list
$IMG
EOF
killall -USR1 xfdesktop

The # xfce backdrop list comment seems to necessary to make it all work.

CRON

CRON is the most natural fit to download new images. So save the script to a place where it can be found, say in ~/bin/xfcebg and edit your user cron entry with crontab -e and put something like this in there

*/5 * * * *       $HOME/bin/xfcebg

That's it!

Didn't like it

The whole scaling seems to be a bit off and the earth image is way too white, so I'm already back on my go'old background :-)