Ubuntu random wallpaper

wallpaperShuffle.sh

#!/bin/sh

# */5     *     *     *     *         /bin/sh  /home/arthur/wallpaperShuffle.sh > /tmp/cronjob.log 2>&1

REAL_UID=$(id --real --user)
PID=$(pgrep --euid $REAL_UID gnome-session | head -n 1)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2- | sed -e "s/\x0//g")

PIC=$(ls /media/arthur/Fast\ Stuff/Cloudbox/Ultrawide\ wallpapers/* | shuf -n1 )
echo $PIC > /home/arthur/log
gsettings set org.gnome.desktop.background picture-uri "file://$PIC"