my %wanted;
my %validfile = map +($_ => 1), qw/ dir file link /;
my %validupdate = map +($_ => 1), qw/ mode owner group /;
for (keys %{ $config{$test}{$tester} }) {
  my($filetype, $updatetype} = split /-/, $_, 2;
  unless ($validfile{$filetype} && $validupdate($updatetype}) {
    warn "Unexpected directive '$_'";
    next;
  }
  $wanted{$filetype}{$updatetype} = $config{$test}{$tester}{$_};
}

[...]

sub wanted_c {
  stat($_);
  my $wanted =
    (-d _ ? $wanted{'dir'})
    : (-l _ ? $wanted{'link'})
    : (-f _ ? $wanted{'file'})
    : return;  # ?? warn unexpected type?
  return unless $wanted;  # nothing to change
  if (defined $wanted->{'mode'}) {
    change_mode($_, $wanted->{'mode'});
  }
  if (defined $wanted->{'owner'}) {
    change_owner($_, $wanted->{'owner'});
  }
  if (defined $wanted->{'group'}) {
    change_group($_, $wanted->{'group'});
  }
}