$re = '/^([0-9a-f]+)_(string[^_]+)_(string[^_]+)_(string[^_]+)_([0-9]+)_([0-9]+)_([^_]+)$/mix';
$str = '10E4558AA0_String1_String2_String3_0_100_12mo';
preg_match_all($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