How can I detect if the user is on localhost in PHP?

Question

In other words, how can I tell if the person using my web application is on the server it resides on? If I remember correctly, PHPMyAdmin does something like this for securi

Answer 1

Newer OS users (Win 7, 8) may also find it necessary to include an IPV6-format remote address in their whitelist array:

$whitelist = array('127.0.0.1', "::1");

if(!in_array($_SERVER['REMOTE_ADDR'], $whitelist)){
    // not valid
}