$re = '/^1(?:[01]\d{2}|200)(?::1(?:[01]\d{2}|200)(?!:)|,1(?:[01]\d{2}|200))*$/m';
$str = '1000
1200
1000:1200
1000,1200
1010:1015,1019,1025:1027
1000,1200,1100
1000:1001:1002
1000,1200,1100,
1201
999
,1111
:1111
:1111,
,1111:';
preg_match_all($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