Show notification when workspace changes for XFCE

#!/bin/bash
# Description: Show notification when workspace changes
# Requires: awk, xfce4-notifyd, libnotify, wmctrl, trap

exitStatusSuccess=0
exitStatusFail=1
scriptname=$(basename -- "$0")
scriptname="${scriptname%.*}"
thisScriptFull=$(readlink -f ${BASH_SOURCE[0]})
thisScriptPathOnly=$(dirname ${thisScriptFull})

# make sure that only one instance of this script is running per user
lockfile=/tmp/.${scriptname}.$USER.lockfile
if ( set -o noclobber; echo "locked" > "$lockfile" ) 2> /dev/null; then
  trap 'rm -f "${lockfile}"; exit $?' INT TERM EXIT
  echo "${scriptname} DEBUG: Locking succeeded" >&2

  sleep 3
  WKS_NUMBER=$(wmctrl -d | awk -v val='*' '$2==val{print $1}')

  while true
  do
    WKS_NUMBER_NEW=$(wmctrl -d | awk -v val='*' '$2==val{print $1}')
    if [ ${WKS_NUMBER} -ne ${WKS_NUMBER_NEW} ]; then
      WKS_NUMBER=${WKS_NUMBER_NEW}
      WKS_NAME=$(wmctrl -d | awk -v val='*' '$2==val{print $10}')
      NUM_DISPLAY=$(( ${WKS_NUMBER} + 1 ))
      notify-send -t 2000 -i cs-workspaces "Workspace Changed" "Workspace changed to \"${WKS_NAME}\" [${NUM_DISPLAY}]"
    fi
    sleep 0.5
  done

# can't create lockfile - notify user and quit
else
  echo "${scriptname} DEBUG: Lock failed, check for existing process and/or lock file and delete exiting: ${lockfile}." >&2
  exit ${exitStatusFail}
fi

exit ${exitStatusSuccess}