my $some_dir = 'c:/';
opendir(DIR, $some_dir) || die "can't opendir $some_dir: $!";
@a =
  sort {(stat "$some_dir/$a")[9] <=> (stat "$some_dir/$b")[9]}
  grep {  -f "$some_dir/$_" }
  readdir(DIR);
closedir DIR;
print join "\n", @a;