Using Regexp::Common you should do this quite easily.

#!/usr/bin/perl -w
use strict;
use Regexp::Common;

my $text = <<TEXT;
   onValidate
   {
    stuff in here
    {
       other stuff
    }
   }
   keep this
   {
       remove this {and {this}}
   }
TEXT

$text =~ s/$RE{balanced}{-parens=>'{}'}//g;

print $text;

[download]

It will print:

   onValidate

   keep this

Update [1] If you'd rather do this without a module, you can try this regular expression:

our $re = qr/(?:\{(?:(?>[^\{\}]+)|(??{$re}))*\})/;

[download]
(I am not a RegEx guru. I got it by just printing $RE{balanced}{-parens=>'{}'} and adjusting it a bit.)

Update [2] And to explain how all this works, here goes:

use YAPE::Regex::Explain;
print YAPE::Regex::Explain->new($re)->explain;

[download]
The regular expression:

(?-imsx:(?:\{(?:(?>[^\{\}]+)|(??{$re}))*\}))

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  (?:                      group, but do not capture:
----------------------------------------------------------------------
    \{                       '{'
----------------------------------------------------------------------
    (?:                      group, but do not capture (0 or more
                             times (matching the most amount
                             possible)):
----------------------------------------------------------------------
      (?>                      match (and do not backtrack
                               afterwards):
----------------------------------------------------------------------
        [^\{\}]+                 any character except: '\{', '\}' (1
                                 or more times (matching the most
                                 amount possible))
----------------------------------------------------------------------
      )                        end of look-ahead
----------------------------------------------------------------------
     |                        OR
----------------------------------------------------------------------
      (??{$re})                run this block of Perl code (that
                               isn't interpolated until RIGHT NOW)
----------------------------------------------------------------------
    )*                       end of grouping
----------------------------------------------------------------------
    \}                       '}'
----------------------------------------------------------------------
  )                        end of grouping
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

[download]

In reply to Re: pattern matching nested { }'s by Caron
in thread pattern matching nested { }'s by Gerard

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.