$message?
=?"Hey,?I'm?spam!?I?like?your?site";

//?Open?blacklist?file
$blacklist?=?file("/home/phpit/public_html/demo/blacklist?spam?php/blacklist.txt");

//?Loop?through?blacklist,?and?check?message
foreach?($blacklist?as?$item)?{
????
//?Check?if?item?isn't?empty?or?comment
????
$item?=?trim($item);

????if?(!empty(
$item)?AND?substr($item,?0,?1)?!=?"#")?{
????????
//?Not?a?comment,?or?empty,?check?message
????????
if?(preg_match("/"?.?$item?.?"/i",?$message,?$match))?{
????????????
//?Blacklisted?URL?found
????????????
die("Sorry,?your?message?has?been?denied?because?a?blacklisted?URL?("?.?$match['0']?.?")?has?been?found.");
????????}
????}
}
?>