#!/usr/bin/perl --

use strict;
use warnings;
use CGI;
use Data::Dump::Streamer;

Main(@ARGV);
exit(0);

BEGIN {
    my %queries = (
# PHP::HTTPBuildQuery
# URL decoded: "foo[bar]=baz", "foo[quick][quack]=schmack"
        "foo%5Bbar%5D=baz&foo%5Bquick%5D%5Bquack%5D=schmack" => {
            foo => {
                bar   => "baz",
                quick => { "quack" => "schmack" },
            },
        },

    );

    sub Main {
        for my $query ( keys %queries ) {
            my $q = CGI->new($query);
            print $query, "\n", Dump( $queries{$query}, parse_str($q) ), "\n";
        }
    } ## end sub Main
} ## end BEGIN

sub parse_str {
    my ($q) = @_;
    my %params;

    for my $k ( $q->param ) {
        my @v     = $q->param($k);
        my $level = \%params;

#~ my @k = grep length, split /\[([^\[]+)\]/, $k;
#~ use DDS; warn Dump( { " $k   => ", [ $k =~ /([^\[\]]+)/g ] } );
        my @items = $k =~ /([^\[\]]+)/g;
        my $key = pop @items;
        for (@items) {
            $level->{$_} ||= {};
            $level = $level->{$_};
        }
        $level->{$key} = \@v;
    } ## end for my $k ( $q->param )
    return \%params;
} ## end sub parse_str

__END__
foo%5Bbar%5D=baz&foo%5Bquick%5D%5Bquack%5D=schmack
$HASH1 = { foo => {
           bar   => 'baz',
           quick => { quack => 'schmack' }
         } };
$HASH2 = { foo => {
           bar   => [ 'baz' ],
           quick => { quack => [ 'schmack' ] }
         } };