$re = '/^(?:\d+\s*,\s*){1,99}\d+,?\s*$/';
$str = '02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,
02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,
02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610 , 1000031645,1000031653,02241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1012312313123131232102241026,03800063860001,1000012945631,1000018112,1000021645,1000031573,1000031602,1000031610,1000031645,1000031653,02241026 ';
preg_match_all($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