$re = '/(conf\_ant|PV00476|PV00011|PV00501|PV00511|PV00521|PV00496|PV00016|PV00491|PV00516|PV00015|PV00018|PV00506|PV00486|PV00014|PV00481|PV00013|PV00502|PV00494|PV00485|PV00495|PV00019|PV00505|PV00500|PV00504|PV00020|PV00012|PV00479|PV00477|PV00522|PV00520|PV00514|PV00499|PV00510|PV00507|PV00492|PV00475|PV00487|PV00017|PV00512)\.html/m';
$str = '';
preg_match_all($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