$re = '/(traffic|bot|website)-?(bot|traffic|website|4free)/m';
$str = 'trafficbot bot-website
traffic-bot traffic4free
bot-traffic traffic-4free
bottraffic website-4free
bottraffic4free bot-4free
websitebottraffic bot4free
getbottraffic4free trafficbot4free
easy-website-traffic automatedtraffic4free
traffic-website ';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php