#!/usr/bin/perl

use strict;
use warnings;

my $data = <DATA>;
chomp $data;

while () {
    my ($rpos, $lpos) = (0, 0);

    $rpos = index($data, "}", $rpos);
    last if $rpos < 0;

    $lpos = rindex($data, "{", $rpos);
    last if $lpos < 0;

    # $lpos + 1 so we don't extract the the {
    # -1 at the end to exclude the }
    my $extract = substr($data, $lpos + 1, $rpos - $lpos - 1);

    # get rid of these braces.
    substr($data, $lpos, 1) = "<";
    substr($data, $rpos, 1) = ">";

    # if you wanted to replace the entire section including braces
    # substr($data, $lpos, $rpos - $lpos + 1) = "<>";

    print "|${extract}|\n";
}

print "|${data}|\n";

__DATA__
text text {scope 4 text {scope 2 text {scope 1 text} scope 2 text} scope 4 text {scope 3 text} scope 4 text } text text

##</code><code>##

|scope 1 text|
|scope 2 text <scope 1 text> scope 2 text|
|scope 3 text|
|scope 4 text <scope 2 text <scope 1 text> scope 2 text> scope 4 text <scope 3 text> scope 4 text |
|text text <scope 4 text <scope 2 text <scope 1 text> scope 2 text> scope 4 text <scope 3 text> scope 4 text > text text|