1. do not forget to close the directory using closedir
2. using recursion and D as the directory handle can be danagerous; better

sub recurse
{
   my $folder = shift;
   my $dir;
   if(opendir($dir, $folder)) # who needs error checking anyways? me!
   {
      while(defined(my $entry = readdir($dir)))
      {
         next if $entry =~ /^\.\.?$/; # avoiding endless loop :)
         if( -d "$folder/$entry" ){ recurse("$folder/$entry"); }
         else
         { #regular file
         }
      }
      closedir($dir);
   }
}
[download]