$re = '/<(\w+)[^>]+>[^>]+test string/';
$str = '<section class="test-class1"><div><hussain class="test-class2">something else..<mkh>..test string</p></div></section>';
preg_match_all($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