Emacs Lisp: How to add a folder and all its first level sub-folders to the load-path

If I have a folder structure set up like this:

~/Projects
    emacs
        package1
            package1-helpers
        package2
            package2-helpers
            package2-more-helpers
        package3
            package3-helpers

How do I add these folders:

• ~/Projects/emacs
• ~/Projects/emacs/package1
• ~/Projects/emacs/package2
• ~/Projects/emacs/package3

...to the load-path from my .emacs file?

I basically need a short automated version of this code:

(add-to-list 'load-path "~/Projects/emacs")
(add-to-list 'load-path "~/Projects/emacs/package1")
(add-to-list 'load-path "~/Projects/emacs/package2")
(add-to-list 'load-path "~/Projects/emacs/package3")

From stackoverflow

• (let ((base "~/Projects/emacs"))
    (add-to-list 'load-path base)
    (dolist (f (directory-files base))
      (let ((name (concat base "/" f)))
        (when (and (file-directory-p name) 
                   (not (equal f ".."))
                   (not (equal f ".")))
          (add-to-list 'load-path name)))))
  

  Alexander Kojevnikov : Thanks Jouni! Unfortunately I receive an error: "An error has occurred while loading `c:/Users/Alex/AppData/Roaming/.emacs': Symbol's function definition is void: do". I have Emacs 22.2.1 running under Vista.

  Jouni K. Seppänen : Oops - "do" is in cl.el, so you can make the original suggestion work by adding "(require cl)" in the beginning. But I modified the answer to use dolist, which both makes it simpler and avoids the need for cl.el.

  Alexander Kojevnikov : Works as a charm, many thanks!

• I suggest you to use subdirs.el

  Alexander Kojevnikov : That's good to know, thanks!

• Here's something I use in my .emacs:

  (let* ((my-lisp-dir "~/.elisp/")
         (default-directory my-lisp-dir)
         (orig-load-path load-path))
    (setq load-path (cons my-lisp-dir nil))
    (normal-top-level-add-subdirs-to-load-path)
    (nconc load-path orig-load-path))
  

  If you look at the description for normal-top-level-add-subdirs-to-load-path, it's somewhat smart about picking which directories to exclude.

  Masi : Note that this code also include subdirectories at /.elisp.

• This is my hacked up version :P

  (defun add-to-list-with-subdirs (base exclude-list include-list)
    (dolist (f (directory-files base))
   (let ((name (concat base "/" f)))
     (when (and (file-directory-p name)
       (not (member f exclude-list)))
    (add-to-list 'load-path name)
    (when (member f include-list)
     (add-to-list-with-subdirs name exclude-list include-list)))))
    (add-to-list 'load-path base))
  

  This will add all first level dirs from base and exclude the ones in exclude-list, while for the dirs in include-list, it will add all the first level dirs of that dir too.

  (add-to-list-with-subdirs "~/.emacs.d" '("." ".." "backup") '("vendor" "my-lisp"))