If you, like me tend to carry around or “cloud around” a single .emacs file so you end up with similar environments wherever you have an Emacs install, you know it’s a little painful to ensure that you have the same set of basic packages installed on each one of your Emacs installations. As I had mentioned before I don’t use that many third party packages so my Emacs configurations aren’t that complicated, but I always prefer to have the computer remember things so I don’t have to.

As I started using ELPA last year, I decided to investigate if I could use ELPA and a little custom code to download and install the packages that I know I want everywhere. One evening I got bored enough to write a function that tests for the presence of a bunch of basic packages that I want to have on every Emacs install. It’s not trying to be fancy and automate things to the n-th degree as I didn’t want to spend the time each time I start Emacs, so I just have to remember to invoke the function after a new install. Here is the function, in all its simple glory:

(defun install-required-packages ()
  (if (>= emacs-major-version 24)
        (setq package-archives '(("ELPA" . "http://tromey.com/elpa/")
                                 ("gnu" . "http://elpa.gnu.org/packages/")
                                 ("marmalade" . "http://marmalade-repo.org/packages/")
                                 ("melpa" . "http://melpa.milkbox.net/packages/")

        (when (not (require 'bm nil t))
          (package-install 'bm))
        (when (not (require 'icicles nil t))
          (package-install 'icicles))
        (when (not (require 'smex nil t))
          (package-install 'smex))
        (when (not (require 'zenburn-theme nil t))
          (package-install 'zenburn-theme))

11 thoughts on “Install your basic Emacs packages via a single function call”

  1. http://stackoverflow.com/questions/14836958/updating-packages-in-emacs/14838150#14838150

    This is similar to yours, except it uses package-installed-p instead of require. Some of my packages are require’d, but as much as possible I just let them autoload, which makes emacs start faster (probably only your theme needs to be require’d). Also, I only package-refresh-contents if it’s a fresh install, but that’s because I run this code at every start up.

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