获取客户端IP

/**
 * 获取客户端IP
 */
function get_ip()
{
    //ip地址
    $realip = '';

 

    if (isset($_SERVER)) {
        if (isset($_SERVER[HTTP_X_FORWARDED_FOR])) {
            $realip = $_SERVER[HTTP_X_FORWARDED_FOR];
        } elseif (isset($_SERVER[HTTP_CLIENT_IP])) {
            $realip = $_SERVER[HTTP_CLIENT_IP];
        } else {
            $realip = $_SERVER[REMOTE_ADDR];
        }
    } else {
        if (getenv("HTTP_X_FORWARDED_FOR")) {
            $realip = getenv("HTTP_X_FORWARDED_FOR");
        } elseif (getenv("HTTP_CLIENT_IP")) {
            $realip = getenv("HTTP_CLIENT_IP");
        } else {
            $realip = getenv("REMOTE_ADDR");
        }
    }
    return $realip;
}