$re = '/^(\S+) (\S+) (\S+) \[([\w:\/]+\s[+\-]\d{4})\] "(\S+)\s?(\S+)?\s?(\S+)?" (\d{3}|-) (\d+|-) (\S+) "(\S+)" "(.+)" "-"$/';
$str = '66.175.239.30 - - [01/Jan/2018:00:30:40 -0500] "POST /wp-cron.php?doing_wp_cron=1514784640.8263568878173828125000 HTTP/1.1" 200 - missinglinksbrewery.com "http://missinglinksbrewery.com/wp-cron.php?doing_wp_cron=1514784640.8263568878173828125000" "WordPress/4.9.1; http://missinglinksbrewery.com" "-"';
preg_match_all($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