Tutorial Get Users IP Address

Accounts for proxies:

if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
     $ip=$_SERVER['HTTP_CLIENT_IP'];
} elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
     $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
} else {
     $ip=$_SERVER['REMOTE_ADDR'];
}

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