#!/usr/bin/perl

use warnings;
use strict;

$\ = $/;

$_ = reverse "(a+b)*c"; # or some longer sequence

s/\)([^()]+)\(/]$1[/g;

print scalar reverse y/][/)(/r;

##</code><code>##

syntax error at ./bracket.pl line 13, near "y/][/)(/r;"
Execution of ./bracket.pl aborted due to compilation errors.

##</code><code>##

s/\)([^()]+)\(/]$1\[/g; # '[' is not a metachar here

##</code><code>##

s/\)([^()]+)\(/]${1}[/g; 
# to surround the whole variable name which is interpreted inside a string