function getRealUserIp(){
    switch(true){
      case (!empty($_SERVER['HTTP_X_REAL_IP'])) : return $_SERVER['HTTP_X_REAL_IP'];
      case (!empty($_SERVER['HTTP_CLIENT_IP'])) : return $_SERVER['HTTP_CLIENT_IP'];
      case (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) : return $_SERVER['HTTP_X_FORWARDED_FOR'];
      default : return $_SERVER['REMOTE_ADDR'];
    }
 }

function count($count_file, ip_file){
    $ip = getRealUserIp();

    if(!in_array($ip, file($ip_file, FILE_IGNORE_NEW_LINES))){
            $hit = (file_exists($count_file)) ? file_get_contents($count_file) : 0;
            file_put_contents($ip_file, $ip."\n", FILE_APPEND);
            file_put_contents($count_file, ++$hit);
            return $hit;
    }
}

if(!file_exists($count_file)){ fopen($count_file, 'w'); }
if(!file_exists($ip_file)){ fopen($ip_file, 'w'); }

echo count('counter.txt','ip.txt');