PHP/Apache2: How do I redirect ./index.php?facebook to ./facebook.php? [duplicate]

There are at least two ways to do it.

• With Apache’s mod_rewrite:

    RewriteEngine On
    RewriteCond %{QUERY_STRING} =facebook [NC]
    RewriteRule (.*)/index.php$ $1/facebook.php [R,L]

• Within the index.php PHP script itself (my PHP is very rusty; consider this to be pseudo-code):

    if (isset($_GET['facebook'])) {
        header('Location: facebook.php');
        exit;
    }