Random wallpaper

#!/bin/bash
# Fetches a random wallpaper from /r/wallpapers
# and sets xfdesktop's wallpaper to it
#
# Author: Michael Koch (emkay443) (and others on reddit: http://redd.it/25wkxa)
# Version: 2014-05-19_1
# License: GPL v3

# get XDG variables
. $HOME/.config/user-dirs.dirs

# configuration
wp_file=$XDG_PICTURES_DIR/wpotd
random=true
monitors=( 0 1 )

# helper variable
if $random; then
    url=$(curl -s http://www.reddit.com/r/wallpapers/.rss | grep -o "http://i.imgur.com/[/a-zA-Z0-9.]\+" | shuf -n 1)
else
    url=$(curl -s http://www.reddit.com/r/wallpapers/.rss | grep -o "http://i.imgur.com/[/a-zA-Z0-9.]\+" | head -1)
fi

# download image
wget -O $wp_file "$url"

# make sure, DBUS is loaded correctly (make this script work with cron)
if [ -z "${DBUS_SESSION_BUS_ADDRESS}" ] ; then
    . ${HOME}/.dbus/session-bus/`ls -rt ${HOME}/.dbus/session-bus/ | tail -1`
        export DBUS_SESSION_BUS_ADDRESS
fi

for mon in "${monitors[@]}"; do
    # set xfdesktop's wallpaper and refresh
    DISPLAY=:0 xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitor$mon/image-path -s $wp_file
    DISPLAY=:0 xfdesktop --reload
done