Select Code to Download

my $dir = "/my_dir";
opendir DIR, $dir or die "$dir: $!\n";
...
my $latest_dir = ( sort {$subdir{$a}<=>$subdir{$b}} keys %subdir )[0];

# ...

my $latest_dir =
  ( map{s/(....)(....)/$2$1/; $_} sort map{s/(....)(....)/$2$1/; $_}
    grep /^\d{8}$/, readdir DIR )[-1];