getdents() on Linux (since 2.6.4) includes a file type (block/character device, directory, pipe, symlink, file, unix domain socket) in the dirent structure directly, so that shouldn't be necessary - certainly ls on my machine just calls getdents() and still produces the type indication.

(also "-f" turns off the colors and type indication in any case, making it a more portable way of ensuring you get fast output even on systems which doesn't embed the type in getdents() results)