Here are the steps for Emacs running on Snow Leopard 10.6.8 using coreutils installed through macports:
NOTE: My macports installation is different than the generic (/opt/...) -- i.e., I use /macports as the root. Altering the root setup is not required, it is just a personal preference of mine. For vanilla macport installations or alternative setups, adjust the path accordingly.
sudo /macports/bin/port install coreutils
This goes inside the .emacs or init.el:
;; sort directories first
(setq insert-directory-program "/macports/bin/gls")
(setq dired-listing-switches "-aBhl --group-directories-first")
NOTE: Using a symlink for gls/ls is not recommended because it breaks functionality with macports install and most likely other stuff too.
Alternative installation for users who want more control:
Download: coreutils-8.21.tar.xz from: http://ftp.gnu.org/gnu/coreutils/
If you do not have a utility to unzip an *.xz file, you can use a utility such as TheUnarchiver3.9.1.
Here is a quick reference to make the coreutils -- I set the installation location to my own personal preference instead of the default:
./configure \
--prefix=/Users/HOME/.0.data/.0.emacs/elpa
make
sudo make install
Insert these into your .emacs or init.el file -- adjust the path accordingly:
;; sort directories first
(setq insert-directory-program "/Users/HOME/.0.data/.0.emacs/elpa/bin/ls")
(setq dired-listing-switches "-aBhl --group-directories-first")