Set gnome desktop background from random image in specified directory
Usage:
wp_rotate <dirname>
Can be used with crontabs for automatic rotation
Example:
# set DBUS_SESSION_BUS_ADDRESS to enable gsettings through cron
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
*/5 * * * * wp_rotate $HOME/Documents/wallpapers