- preg_match: documentation ( source)
<?php
$agent = 'bot';
if ($agent=='' || preg_match('#(MEGAUPLOAD|Feedfetcher|YisouSpider|HTTrack|HTTPClient|SurveyBot|Anonymous|similarpages|webcollage|MJ12bot|WebCopier|Teleport|ISpider|Wget|Offline|WebSnake|Download|Ezooms|Exabot|Gigabot|DotBot|psbot)#',$agent))
echo 1;
else
echo 0;