while (defined( my $fn = readdir($dh) )) {
   my $qfn = "$dir_qfn/$fn";
   ...
}

##</code><code>##

sub load {
   my ($pkg) = @_;
   my $qfn = $pkg =~ s{::}{/}gr . '.pm';
   ...
}

##</code><code>##

for my $qfn (glob("\Q$dir_qfn\E/*")) {
   stat($qfn)
      or do {
         warn("Skipping \"$qfn\": Can't stat: $!\n");
         next;
      };

   next if !-d _;

   ...
}

##</code><code>##

for my $subdir_qfn (glob("\Q$dir_qfn\E/*")) {
   stat($qfn)
      or do {
         warn("Skipping \"$subdir_qfn\": Can't stat: $!\n");
         next;
      };

   next if !-d _;

   ...
}

##</code><code>##

for my $subdir_qfn (
   grep {
      if (stat($_)) {
         -d _
      } else {
         warn("Skipping \"$_\": Can't stat: $!\n");
         0
      }
   }
      glob("\Q$dir_qfn\E/*")
) {
   ...
}