use File::Find;

sub dirs_only {
   my ($array_ref) = @_;
   return sub {
      return unless -d $_;
      push(@$array_ref, $File::Find::name);
   };
}

{
   # Not a global.
   my @dirlist;

   find(dirs_only(\@dirlist), shift(@ARGV));

   # Use @dirlist here
}