SOURCE_FILE=$(realpath -m "$1")
TARGET_FILE=$(realpath -m "$2")

if [[ -f "${TARGET_FILE}" ]]; then
  TEMP_FILE=$(mktemp)
  awk -F '=' 'NR==FNR{a[$1]=$0;next}($1 in a){$0=a[$1]}1' "${SOURCE_FILE}" "${TARGET_FILE}" > "${TEMP_FILE}"
  mv "${TEMP_FILE}" "${TARGET_FILE}"
else
  mkdir -p "$(dirname "${TARGET_FILE}")"
  cp "${SOURCE_FILE}" "${TARGET_FILE}"
fi

echo "Configuration file ${TARGET_FILE} has been updated."