Get Current IP Address Using PhP

$user_agent = getenv("HTTP_USER_AGENT");

if(strpos($user_agent, "Win") !== FALSE)
{
    $db_user = ($_SERVER['HTTP_HOST'] == 'localhost' || $_SERVER['HTTP_HOST'] == getHostByName(getHostName())) ? 'root' : 'database_name';
    $db_pass = ($_SERVER['HTTP_HOST'] == 'localhost' || $_SERVER['HTTP_HOST'] == getHostByName(getHostName())) ? '' : '';
}elseif(strpos($user_agent, "Mac") !== FALSE){
    $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
    $res = socket_connect($sock, '8.8.8.8', 53);
    // You might want error checking code here based on the value of $res
    socket_getsockname($sock, $current_ip); // Use $current_ip Variable For The Mac Current IP Address
    socket_shutdown($sock);
    socket_close($sock);

    $db_user = ($_SERVER['HTTP_HOST'] == 'localhost' || $_SERVER['HTTP_HOST'] == $current_ip) ? 'root' : 'database_name';
    $db_pass = ($_SERVER['HTTP_HOST'] == 'localhost' || $_SERVER['HTTP_HOST'] == $current_ip) ? '' : '';
}