Question

I am looking for a way to interpret data in a URL, server side.
Client side, I can control what the URL is, and I can programmatically produce Data for the URL, but I do not have direct access to the source code.

So ultimately, I am trying to build an online High Score system, for an offline game.

I have access to Azure and my dedicated LAMP server. I would like for my server to wait for a connections that use a URL something like “http://www.myappserver19002393859.com/HighScores?UserID=2fb44e3888?Score=25250”
I want to get the UserID & Score from the URL and then redirect to another page with the High Score Table…

Any suggestions?

(Edit: I can do anything server side, it is only client side where I have limitations.)

Answer 1

Use PHP’s $_GET collection. It contains the key/value pairs of a URI’s querystring.

In the example you’ve given, it would look like this:

HighScoresHandler.php

<?php
$userId = $_GET['UserID'];
$score  = $_GET['Score'];

// Validation

if( empty( $userId ) || empty( $score ) ) {
    echo "No UserID or Score provided.";
    exit();
}
$score = intval( $score );
if( $score === 0 ) {
    echo "Invalid score specified.";
    exit();
}

// Verification

// TODO: Query your database to ensure the user specified by $userID exists.
// Make sure you do this safely as not to be subject to SQL injection.

$sql = "SELECT COUNT(*) FROM Users WHERE UserID = @userId";

// Action

$sql = "INSERT INTO HighScores ( UserID, Score ) VALUES ( @userId, @score )";


?>

Note that you would be advised to implement some form of MAC (Message Authentication Code) or some other system to verify that a score is real, otherwise there is nothing stopping anyone from submitting bogus scores using forged HTTP requests (this is why you sometimes see insanely high scores posted to online scoreboards).