$re = '/(\w+)="(\d+)"/';
$str = '<log pos_start="40652288" end_position="40689664" log_type="1" length="37376" block_id="4024" block_position="18"/>';
preg_match_all($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