php ile birden fazla ülkeden girişi engellemek?

<?php
function Turk_mu($url_csv){
$curl_handle = curl_init();
curl_setopt($curl_handle, CURLOPT_URL, $url_csv);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
$str_fromfile = curl_exec($curl_handle);
curl_close($curl_handle);
$range = explode("\n", $str_fromfile);

$ip_addr = getenv(REMOTE_ADDR); //gets the IP of the visitor
$ip_byte = explode('.', $ip_addr);
$ip_number = (16777216 * (int) $ip_byte[0]) + (65536 * (int) $ip_byte[1]) + (256 * (int) $ip_byte[2]) + ((int) $ip_byte[3]);

for($i = 0; $range[$i] != NULL && $is_positive == NULL; $i++){ // the condition $line[$i] != NULL means that you should not put blank lines before the end of your CSV. The values should start at line 1.
    $range[$i] = rtrim(ltrim($range[$i])); //you may remove this if you are sure the CSV doesnt contain whitespaces
    $ends_addr = explode(',', $range[$i]); //for CSV (comma-separated values), comma is the separator. You may change this if your TXT uses different separator.
    $ends_addr[0] = rtrim($ends_addr[0]); //again, you may remove this if your CSV is free from whitespaces
    $ends_addr[1] = ltrim($ends_addr[1]); //yet, again
    $start_ip_byte = explode('.', $ends_addr[0]);
    $end_ip_byte = explode('.', $ends_addr[1]);
    $start_ip_number = (16777216 * (int) $start_ip_byte[0]) + (65536 * (int) $start_ip_byte[1]) + (256 * (int) $start_ip_byte[2]) + ((int) $start_ip_byte[3]);
    $end_ip_number = (16777216 * (int) $end_ip_byte[0]) + (65536 * (int) $end_ip_byte[1]) + (256 * (int) $end_ip_byte[2]) + ((int) $end_ip_byte[3]);
      
    if($ip_number >= $start_ip_number && $ip_number <= $end_ip_number)
            $is_positive = 1;
}
  
    if($is_positive == 1)
        return true;
    else
        return false;
}

if(Turk_mu('http://test.divxklip.net/turkey.txt') === true)
      echo 'Turkiye Ziyaretci';
?>