how to capture group within capture group?

Question

for example, string:

bla bla bla (bla oops bla
bla bla bla 
bla bla bla) bla oops
bla bla bla 
oops bla (bla bla oops
bla)

how i can get 'oops' between brackets? first, i get text between brackets:

(?<=\()([\w\W]*?)(?=\))

can i in the same regex capture group within capture group (find 'oops' within capture group)?

If you have PHP, `\([^()]*\Koops(?=[^()]*\))`. In .NET, `(?<=\([^()]*)oops(?=[^()]*\))`. — Wiktor Stribiżew, Nov 27 '18 at 17:31
See https://stackoverflow.com/questions/23342679/match-specific-word-between-brackets, too — Wiktor Stribiżew, Nov 27 '18 at 17:34
Eventually, a lot depends on what you need to get in the end (usually, extract or replace). — Wiktor Stribiżew, Nov 27 '18 at 17:46
@WiktorStribiżew thank you so much for php-regex!!!!!!!!! Now I understand how `\K` works. — Alexander, Nov 28 '18 at 04:28
and also i didn't know that quantifiers work whithin lookahead/lookbehind in some languages (e.g. .NET). Thank you for that information. — Alexander, Nov 28 '18 at 05:22
i've one more question. can i get multiple "oops" whithin brackets (on PHP, i.e without quantifiers whithin lookahead/lookbehind)? if string:bla bla bla (bla oops bla bla oops bla bla bla bla bla) bla oops bla bla bla oops bla (bla bla oops bla) — Alexander, Nov 28 '18 at 05:38

score 1 · Accepted Answer · answered Nov 28 '18 at 08:15

You may use

(?:\G(?!\A)|\()[^()]*?\Koops

Or, if you must check for the closing parentheses, add a lookahead at the end:

(?:\G(?!\A)|\()[^()]*?\Koops(?=[^()]*\))

Details

(?:\G(?!\A)|\() - ( or end of the previous match (\G(?!\A))
[^()]*? - any 0+ chars other than ( and )
\K - match reset operator
oops - the word you need (wrap with \b if you need a whole word match)
(?=[^()]*\)) - a positive lookahead that requires 0+ chars other than ( and ) up to the first ) to appear immediately to the right of the current location.

thank you very much. You made me study regular espressions in more detail. thanks again. — Alexander, Nov 28 '18 at 08:39

score 0 · Answer 2 · answered Nov 27 '18 at 17:39

0

You can use the following regex:

(?<=\()([\w\W]*?(oops)[\w\W]*?)(?=\))

Basically it injects a Group looking for 'oops' then it doubles the '[\w\W]*?' matching both before and after the captured Group.

Now 'oops' will be in Group 2.

answered Nov 27 '18 at 17:39

Poul Bak

2 Answers2