Simple example of PHP anti-hotlinking (available for testing)

<?php
/*
* 防止盗链
*调用url格式：文件名?site=1&file=文件  
例，http://bbs.it-home.org/down.php?site=1&file=validatecode.rar 
*/
$ADMIN[defaulturl] = "http://bbs.it-home.org/404.htm";//盗链返回的地址
$okaysites = array("http://bbs.it-home.org/","http://jbxue.com"); //白名单 
$ADMIN[url_1] = "http://bbs.it-home.org/download/";//下载地点1
$ADMIN[url_2] = "";//下载地点2，以此类推

$reffer = $HTTP_REFERER;
if($reffer) {
$yes = 0;
while(list($domain, $subarray) = each($okaysites)) {
if (ereg($subarray,"$reffer")) {
$yes = 1;
}
}
$theu = "url"."_"."$site";
if ($ADMIN[$theu] AND $yes == 1) {
header("Location: $ADMIN[$theu]/$file");
} else {
header("Location: $ADMIN[defaulturl]");
}
} else {
header("Location: $ADMIN[defaulturl]");
}
?>