This script is designed to run as a php auto-prepend, like so (in .htaccess)..
php_value auto_prepend_file "/real/full/server/path/to/anti-hammer.php"
If you are running PHP as a CGI, put a line in your local php.ini/.user.ini file, instead:
auto_prepend_file = "/real/full/server/path/to/anti-hammer.php"