Emacs function to add new path elements to the $PATH environment variable

A very simple eLisp function to add new path elements to the PATH environment variable. Very useful for adding new comint executables from within .emacs/init.el files.

(defun my-add-path (path-element)
 "Add the specified path element to the Emacs PATH"
  (interactive "DEnter directory to be added to path: ")
  (if (file-directory-p path-element)
    (setenv "PATH"
       (concat (expand-file-name path-element)
               path-separator (getenv "PATH")))))