I am looking for some help. I am unsure if it is possible to match an outside group and also match inside the group if exists.

for example:

10/22/2021 8:56:35 test Warning ID: 111 OD: 00:00:01 blah blah blah blah

I want to

• group date: 10/22/2022
• group time: 8:56:35
• group proc: test
• group log_level: Warning
• group ID(if exist): ID: 111
• group message: test Warning ID: 111 OD: 00:00:01 blah blah blah blah

Regex appears to almost work but fails if ID is not present. I only want to capture ID if we match, else just capture the message.

^(?<date>(?:\d )\/\d \/\d )\s (?<time>(?:\d :){2}\d )\s (?<proc>\w )\s(?<log_level>\w )\s(?<message>.*(?:ID: (?<ID>\d )).*)$

I want to match the ID group 0 or 1 times (?) but when i add ? to the group it breaks the regex for the message group. ie:

^(?<date>(?:\d )\/\d \/\d )\s (?<time>(?:\d :){2}\d )\s (?<proc>\w )\s(?<log_level>\w )\s(?<message>.*(?:ID: (?<ID>\d ))?.*)$

Any help would be greatly appreciated

CodePudding user response：

You can use

^(?<date>(?:\d )\/\d \/\d )\s (?<time>(?:\d :){2}\d )\s (?<proc>\w )\s(?<log_level>\w )\s(?<message>.*?(?:ID: (?<ID>\d ).*)?)$

See the regex demo.

The only change is in Group "message" pattern, that now looks like (?<message>.*?(?:ID: (?<ID>\d ).*)?). It matches

• .*? - any zero or more chars other than line break chars as few as possible
• (?:ID: (?<ID>\d ).*)? - an optional non-capturing group that matches
  • ID: - a fixed string
  • (?<ID>\d ) - Group "ID": one or more digits
  • .* - any zero or more chars other than line break chars as many as possible.