The original question: I have a data looking like : $data = (D,(A,B),C) When searching for A, I want to extract (A,B) and cut it out form the $data. I am not sure how to get the nearest "(" of A. Is there a regex for that?

Not the clearest description, but if you mean you want to search for 'A', and remove it and everything within the nearest set of enclosing parens:

$data = '(D,(A,B),C)';;

$data =~ s{(\([^(]*A[^)]*\))}{} and print "$1\n$data";;
(A,B)
(D,,C)
[download]

Note: the stuff removed is also available in $1.

Yup thats what I wanted. Thanks!

I missed something. I updated the question.

Hi lazycoder,

In researching this a bit I came across Parsing nested parentheses, which has lots of answers to a question similar to yours. There's also perlfaq6, Text::Balanced, and Regexp::Common::balanced.

For fun, I went all-out and parsed the string into a Perl data structure - this is probably overkill for you, but I'll post it anyways in case it's useful to someone.

First, the output:

   $input = '(E,(A,B),(C,(X,Y,Z),D),F)';
  $parsed = ['E,',['A,B'],',',['C,',['X,Y,Z'],',D'],',F'];
$filtered = ['E,',',',',F'];
  $output = '(E,F)';
[download]

And the code:

Hope this helps,
-- Hauke D

Is your data a string? Where does it come from?

There's probably a better way to accomplish what your main goal is. If you describe your situation a little more fully you'll probably get some good suggestions.

XY Problem