^start of string
Group hostip(?<hostip>[^ ]+) Negated Character Class[^ ]+ +matches at least one character outside the set below:
the literal (3210 / 408 / 2016)
\[the literal [ (9110 / 1338 / 5B16)
Group timestamp(?<timestamp>[^ ]+) Negated Character Class[^ ]+ +matches at least one character outside the set below:
the literal (3210 / 408 / 2016)
\sany whitespace character
-the literal - (4510 / 558 / 2D16)
Group unknown1(?<unknown1>\d+) \d+a digit, repeated at least once
Group method(?<method>[^ ]+) Negated Character Class[^ ]+ +matches at least one character outside the set below:
the literal (3210 / 408 / 2016)
the literal (3210 / 408 / 2016)
Group request(?<request>[^ ]+) Negated Character Class[^ ]+ +matches at least one character outside the set below:
the literal (3210 / 408 / 2016)
HTTPthe literal text HTTP (case sensitive) \/the literal / (4710 / 578 / 2F16)
\da digit
\.the literal . (4610 / 568 / 2E16)
\da digit
Group response(?<response>\d+) \d+a digit, repeated at least once
\d+a digit, repeated at least once