$re = '/\(\[(Modulus\(\d+\)(?:\s*,\s*Modulus\(\d+\))*)\]\):(\(\d+(?:,\d+)*\)x\^\d+(?:\s*\+\s*\(\d+(?:,\d+)*\)x\^\d+)*)/m';
$str = 'RNS Polynomial ([Modulus(68719403009), Modulus(68719230977), Modulus(137438822401)]):(67699591241,42814670386,92925202514)x^0 + (42539574637,55054036653,135659663247)x^1 + (52858091297,11618896202,6855552742)x^2 + (45970532823,20845087073,91272562929)x^3 + (11148839321,55275439733,5401722690)x^4 + (31959765643,40620395732,93052536121)x^5 + (57030732406,66026147059,6304524013)x^6 + (27778918692,11276356856,61606736382)x^7
';
preg_match_all($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