$re = '/^(?:[^|]*\|){4}\s*/m';
$str = '172.21.201.135 | http | o@1I0BTOx1063x3667295x0 | hkv | 2020-06-10 17:43:18,951 | "POST /rest/build-status/latest/commits/stats HTTP/1.1" | "http://bitbucket.klp.no/projects/WF/repos/klp-libs/compare/commits" "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36" | 200 | 345 | 431 | - | 5 | 3dk4qm | ';
preg_match_all($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