$re = '/^(?:(?:40\d[0-5]|[1-3]\d{3}|[1-9]\d{2}|[1-9]\d|\d),){3}(?:40\d[0-5]|[1-3]\d{3}|[1-9]\d{2}|[1-9]\d|\d)$/m';
$str = '1200,2500,6500,90
1200,2500,6500,90
1200,2500,4095,90
0,0,0,0
999,1,0,99
000,000,000,000
4095,4095,4095,4095
';
preg_match_all($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