Crontab wallpaper slideshow

#!/bin/bash

# Search these processes for the session variable
# (they are run as the current user and have the DBUS session variable set)
compatiblePrograms=( nemo pulseaudio trackerd nautilus )

# Attempt to get a program pid
for index in ${compatiblePrograms[@]}; do
    PID=$(pidof -s ${index})
    if [[ "${PID}" != "" ]]; then
        break
    fi
done
if [[ "${PID}" == "" ]]; then
    echo "Could not detect active login session"
fi

QUERY_ENVIRON="$(tr '\0' '\n' < /proc/${PID}/environ | grep "DBUS_SESSION_BUS_ADDRESS" | cut -d "=" -f 2-)"
if [[ "${QUERY_ENVIRON}" != "" ]]; then

    export DBUS_SESSION_BUS_ADDRESS="${QUERY_ENVIRON}"
    # echo "Connected to session:"
    # echo "DBUS_SESSION_BUS_ADDRESS=${DBUS_SESSION_BUS_ADDRESS}"

 # Script to randomly set Background from files in a directory

 # Directory Containing Pictures is given via command-line, could be hardcoded in there as well
 DIR=$1

 #DIR="/home/user/Picture"
 #DIR="/home/user/Documents/cultural-festivities/"

 # Command to Select a random jpg file from directory
 PIC=$(find $DIR -type f -exec file {} \; | grep -o -P '^.+: \w+ image' | cut -d ':' -f 1 | shuf -n1)

 # Command to set Background Image
 gsettings set org.cinnamon.desktop.background picture-uri "file:///$PIC"



else
    echo "Could not find dbus session ID in user environment."
fi