[Perl] Method 내에서 전달된 hash 직접 조작하기

#!/usr/bin/perl
use Data::Dumper;
 
my $r_org_h = getHash();
printf "%s", Dumper $r_org_h;
 
sub getHash
{
        my %item = ();
 
        $item{s_item}{domain_a}{company0} = "10";
        $item{s_item}{domain_a}{company1} = "11";
        $item{s_item}{domain_b}{company0} = "20";
        $item{s_item}{domain_b}{company1} = "21";
 
        printf "%s", Dumper \%item;
        changeSiteHash(\%item);
        printf "%s", Dumper \%item;
 
        $item{s_normal}{domain_a} = "3";
        $item{s_normal}{domain_b} = "4";
        $item{s_spam}{domain_a} = "5";
        $item{s_spam}{domain_b} = "6";
        return \%item;
}
 
sub changeSiteHash
{
        my ($r_item) = @_;
        my %new_item = %$r_item;
 
        printf "%s\n", $r_item{s_item}{domain_a}{company0};
        printf "%s\n", $r_item->{s_item}{domain_a}{company0};
        $r_item->{new_item}{new_domain} = "val";
}