my $cnt = 0;
while (...) {
    ...
    $hash{$header} = [$cnt, $inhalt];
    ++$cnt;
    ...
}
...
for my $key (sort { $hash{$a}[0] <=> $hash{$b}[0] } keys %hash) {
    print "$key => $hash{$key}[1]\n";
}