$re = '/(?<field1>\d+)$/m';
$str = 'msg: 2018-07-07 14:30:02.226 INFO 7 --- [nio-8080-exec-6] c.f.p.a.service.CGEventRetimeService : <> : 12006';
preg_match_all($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