cloudflare auto ddns + memory flush

ping.php

#!/usr/bin/php
<?php

/*
 * crontab -e
 * 0 5 * * * ~/ping.php
 */
error_reporting(0);
set_time_limit(0);

$domain = "stypr.com";
$subdomain = "home";
$zone_id = "you need to get this from cloudflare";
$email = "[email protected]";
$token = "you need to get this from cloudflare";


header("Content-Type: text/html; charset=utf-8");
@system("/sbin/sysctl vm.drop_caches=3");

function getfirstIP(){
  $fp = @fsockopen("ip4.me", "80", $errno, $errstr, 3);
  if(!$fp) die("Killed");
  $packet  = "GET / HTTP/1.0\r\n";
  $packet .= "Host: ip4.me\r\n";
  $packet .= "User-Agent: Mozilla/5.0\r\n\r\n";
  @fwrite($fp, $packet);
  while($buffer = fgets($fp, 2048)){
    $test .= fgets($fp, 2048);
  }
  fclose($fp);
  $test = explode("+3>",$test);
  $test = explode("</font", $test[1]);
  return $test[0];
}

function getsecondIP(){
  $fp = @fsockopen("ipip.kr", "80", $errno, $errstr, 3);
  if(!$fp) die("Killed");
  $packet  = "GET / HTTP/1.0\r\n";
  $packet .= "Host: ipip.kr\r\n";
  $packet .= "User-Agent: Mozilla/5.0\r\n\r\n";
  @fwrite($fp, $packet);
  while($buffer = fgets($fp, 2048)){
    $test .= fgets($fp, 2048);
  }
  fclose($fp);
  $test = explode("Your IP is ",$test);
  $test = explode("</title>", $test[1]);
  return $test[0];
}

function getreceiver(){
  $fp = @fsockopen("stypr.com", "80", $errno, $errstr, 3);
  if(!$fp) die("Killed");
  $packet  = "GET /receiver.php?mode=receiver HTTP/1.0\r\n";
  $packet .= "Host: stypr.com\r\n";
  $packet .= "User-Agent: Mozilla/5.0\r\n\r\n";
  @fwrite($fp, $packet);
  $test = fgets($fp, 128);
  fclose($fp);
  die("Success");
}

$first = getfirstIP();
$second= getsecondIP();

if($first == $second){
  @system("curl -s \"https://www.cloudflare.com/api_json.html?a=rec_edit&z=".$domain."&id=".$zone_id."&content=".$first."&ttl=1&name=".$subdomain."&type=A&email=".$email."&tkn=".$token."\"");
}else{
  getreceiver();
}