emailtracking/php/track.php

<?php
require __DIR__ . "/lib/class.EmailTracker.php";

$trackingID = "";
$type = "none";

// check which type was logged
if(isset($_GET["img"])) {
    $trackingID = $_GET["img"];
    $type = "img";
} else if(isset($_GET["sound"])) {
    $trackingID = $_GET["bgsound"];
    $type = "bgsound";
}

if(!empty($trackingID) && $type !== "none") {
    $dbObj = new EmailTracker();

    // build our tracking entry
    $data = array(
        "ip_addr" => $_SERVER["REMOTE_ADDR"],
        "referrer" => isset($_SERVER["HTTP_REFERER"]) ? $_SERVER["HTTP_REFERER"] : "",
        "client" => isset($_SERVER["HTTP_USER_AGENT"]) ? $_SERVER["HTTP_USER_AGENT"] : "",
        "tracking_type" => $type,
        "timestamp" => date('Y-m-d H:i:s', time()),
    );

    // log it to db
    $dbObj->addLog($trackingID, $data);
} else {
    echo "Powerful you have become, the dark side I sense in you.";
}