Used with udev to sync a backup drive.

sync-backup-drive.sh

#!/bin/bash

drive_name="${1}"
if [ -z "${drive_name}" ]; then
    exit 1
fi

USERNAME='username'
SOURCE_DIR="/home/${USERNAME}/Backup"

function notify() {
    su "${USERNAME}" -c "DISPLAY=:0.0 /usr/bin/notify-send '${1}'"
}

# Wait for Ubuntu to auto-mount the drive.
drive_dir=
while [ -z "${drive_dir}" ]; do
    sleep 2
    drive_dir="$(grep "${drive_name}" /etc/mtab | awk '{print $2}')"
done

notify "Syncing ${drive_dir}"
HOME=/root unison "${SOURCE_DIR}" "${drive_dir}" -batch -prefer newer -times=true -perms 0
notify "Finished syncing ${drive_dir}"