ver=$(bash --version | head -n 1 | awk '{print $4}' | grep -o "\.\..")
check_ver=$(echo -e "${ver}\n4.3" | sort -V | head -n 1)
if [[ "${ver}" == "${check_ver}" ]]; then
  echo "[${USER}@${HOSTNAME} ${PWD##*/}]$ "
else
  echo "${PS1@P}"
fi