$re = '/<a href=([^<]*)test2.com([^<]*)<\/a>/';
$str = '<a href="test1.com">test1</a><a href="test2.com">test2</a>';
preg_match_all($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