use strict;
use warnings;
system "cls";

my $filnr;
my $sn;
open SERVICE, "datei.csv" 
    or die "Kann datei.csv nicht oeffnen ($!)";
while (<SERVICE>){
    if (defined ($_)){
        $nr=((split /;/,$_)[0]);
        $sn=((split /;/,$_)[6]);
        my %sn_service = {
            "$sn" => "$nr",
#            $fake_sn => $fake_filnr,
        }
    }
}