#!/bin/bash

get_old_ip(){
  if [ -f "${1}"ip.txt ]; then
    OLD_IP=$(cat "${1}"ip.txt 2>/dev/null)
    if [ -z "${OLD_IP}" ]; then
      return 1
    else
      return 0
    fi
  else
    return 1
  fi
}

get_cur_ip(){
  CUR_IP=$(curl ifconfig.me 2>/dev/null)
  if [ -z "${CUR_IP}" ]; then
    return 1
  else
    return 0
  fi
}

get_old_ip "${1}" && {
  get_cur_ip "${1}" && {
    [ "${OLD_IP}" == "${CUR_IP}" ] && {
      echo -n "${CUR_IP}" > "${1}"ip.txt
      echo -n "${CUR_IP}"
      exit 0
    }\
    || {
      echo -n "${CUR_IP}" > "${1}"ip.txt
      echo -n "${CUR_IP}"
      exit 0
    }
  }
}\
|| get_cur_ip "${1}" && {
  echo -n "${CUR_IP}" > "${1}"ip.txt
  echo -n "${CUR_IP}"
  exit 0
}
exit "${?}"