#!/usr/bin/perl
use strict;
use warnings;
use Fcntl qw(:DEFAULT :flock);
use Date::Calc;
use Data::Dumper;
local $Data::Dumper::Purity = 1;
local $Data::Dumper::Useqq = 1;
local $Data::Dumper::Deparse = 1;
local $Data::Dumper::Sortkeys = sub {
	my ($hash) = @_;
	return [(sort {lc $a cmp lc $b} keys %$hash)]; 
};
use 5.010;

my %code = (
	testsub => sub{
		my ($coderef,$irgendwasref,$io) = @_;
		say "zu Beginn: ".Dumper($io);

		my %tmp_io = %$io;
		say "innen vorher : ".Dumper($io);
		$tmp_io{verkn} = $io->{verkn}{unterschluessel};
		say "innen nachher: ".Dumper($io);

		say "Kopie        : ".Dumper(\%tmp_io);
	},
);

my %irgendwas = (schluessel => {unterschluessel => {unterunter => 7}});
my %start = (
	foo		=> 2,
	verkn	=> $irgendwas{schluessel},
);

say "außen vorher : ".Dumper(\%start);
$code{testsub}->(\%code,\%irgendwas,\%start);
say "außen nachher: ".Dumper(\%start);