Background not changing using gsettings from cron

Editing gsettings from cron; missing environment variable

If you run the script from your own environment (e.g. from a terminal window or from Startup Applications), a number of environment variables will be set. cron however runs your script with a limited set of environment variables.

To edit gsettings successfully from cron, you need to set the DBUS_SESSION_BUS_ADDRESS environment variable. You can do that by adding two lines to your script, as described here (and below).

Your script, including setting the needed variable

The script from here, edited to include the DBUS_SESSION_BUS_ADDRESS environment variable, then becomes:

#!/bin/bash

PID=$(pgrep gnome-session)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)

DIR="/home/indra/Pictures/wallpapers"
PIC=$(ls $DIR/* | shuf -n1)
gsettings set org.gnome.desktop.background picture-uri "file://$PIC"

Related: Running .sh every 5 minutes