# Store your values in a hash of hashes
# $kols{line1} = { date => 12-12-06, bits => 12, ... }

my $orderby = "date" # or "bits, ..."
my $updown = "DESC" # or "ASC"
foreach (sort { &mysort($updown) } keys %kols) {

} # end-foreach

sub mysort {
        my ($direction) = @_;
        if ($direction eq "DESC") {
                $kols{$b}{$orderby} <=> $kols{$a}{$orderby}
                ||
                $kols{$b}{$orderby} cmp $kols{$a}{$orderby}
        } # end-if
        else {
                $kols{$a}{$orderby} <=> $kols{$b}{$orderby}
                ||
                $kols{$a}{$orderby} cmp $kols{$b}{$orderby} 
        } # end-else 
} # end-sub