use strict;
use warnings;

#!usr/bin/perl

print "here I start \n";
do "Datei_mit_Subroutine.pl";



my %hash = %{dateilesen()};

print "here is the return value of dateilesen:\n";

foreach my$key (sort {$hash{$a}->[0] <=> $hash{$b}->[0]}keys %hash)
 {
    print "$key: ";
foreach my $val (@{$hash{$key}}) {
        print "$val ";
    }
print "\n";
}

 sub dateilesen {
        my %hash;
        $hash{h12} = [qw/121 122 123/];
        $hash{h15} = [qw/151 152 153/];
\%hash; } 

here I start
here is the return value of dateilesen:
h12: 121 122 123
h15: 151 152 153