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

$count_file = 'counter.txt';
$ip_file = 'ip.txt';

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

echo vcount($count_file,$ip_file);