Bash - Assign key=value arguments to variables

# Parse key=value arguments from ARGV
for arg in "$@"; do
  if [[ $arg =~ ^([a-z_]+)=(.*)$ ]]; then
    key=${BASH_REMATCH[1]}
    value=${BASH_REMATCH[2]}
    case $key in
      hipchat_room)   HIPCHAT_ROOM="$value" ;;
      hipchat_from)   HIPCHAT_FROM="$value" ;;
      hipchat_token)  HIPCHAT_TOKEN="$value" ;;
      hipchat_notify) HIPCHAT_NOTIFY="$value" ;;
      clear)          E_CLEAR="$value" ;;
      status)         E_STATUS="$value" ;;
      created)        E_CREATED="$value" ;;
      updated)        E_UPDATED="$value" ;;
      severity)       E_SEVERITY="$value" ;;
      device)         E_DEVICE="$value" ;;
      summary)        E_SUMMARY="$value" ;;
      eventclass)     E_EVENTCLASS="$value" ;;
      component)      E_COMPONENT="$value" ;;
      count)          E_COUNT="$value" ;;
      ownerid)        E_OWNERID="$value" ;;
      firstseen)      E_FIRSTSEEN="$value" ;;
      lastseen)       E_LASTSEEN="$value" ;;
      evturl)         E_EVTURL="$value" ;;
      ackurl)         E_ACKURL="$value" ;;
      devurl)         E_DEVURL="$value" ;;
    esac
  fi
done