if($_SESSION['token'] == NULL){ $_SESSION['token'] = rand(1111,9999); } if ( filter_input( INPUT_GET, 'r' ) == $_SESSION['token']){ $_SESSION['token'] = rand(1111,9999); } echo '<a href="/link?r='.$_SESSION['token'].'/"> Test</a>';
function gen_token() { $token = sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x', mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0x0fff) | 0x4000, mt_rand(0, 0x3fff) | 0x8000, mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff) ); return $token; } echo gen_token(); // a30c8d89-f2aa-4af9-b1df-6b6443349706
<?php $rand = mt_rand(); switch ($rand) { case $rand: echo 'Hello World!'; break; }