If your trying to cut it down then you don't really need the hash, since an array dereference is maybe/probably faster than a hash lookup.

my $dir   = shift || ".";
my $field = shift || 10;
opendir(DIRH, $dir) or die "Cannot open $dir: $!";
for (
    sort { $b->[1], $a->[1] }
    map  { [ $_, (stat("$dir/$_"))[$field] ] }
    grep { !/^\.\.?$/ && /pm$/ }
    readdir(DIRH)
    ) {
        print join("\t", @$_) . "\n";
}
closedir(DIRH);
[download]

Update: fixed a few errors, which turnstep pointed out.