my %datensaetze;
# ... der Code von oben...

# Liste der Namen der gefundenen Datenlisten
print join(', ',keys(%datensaetze))."\n";

for my $main_key (keys(%datensaetze))
{
 print "- $main_key\n";
 for my $sub_key (keys(%{$datensaetze{$main_key}}))
 {
  print "     $sub_key = ";
  # wert zum schlüssel:
  print $datensaetze{$main_key}{$sub_key}."\n"
 }
 print "\n";
}

while(my ($main_key,$hashref)=each(%datensaetze))
{
 while(my ($sub_key,$value)=each(%$hashref))
 {
  print "$main_key -> $sub_key = $value\n";
 }
 print "\n";
}