$re = '/\([\s\S]*[^\\\\]{1}\)?/m';
$str = '(Mozilla/5.0 \\(X11; Linux x86_64\\) AppleWebKit/537.36 \\(KHTML, like Gecko\\) Chrome/data Safari/data2) /Producer (Skia/PDF m80) /CreationDate (D:20200420090009+00\'00\') /ModDate (D:20200420090009+00\'00\')';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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