More Adventures in Emacs Land

I’m now using Emacs on my three computers, an Apple iBook, a Windows desktop and a Linux desktop. The problem is keeping a uniform set-up over the three.

I used to use jEdit, which remains an excellent text editor that I would use, and recommend, in an instant. It is, in many ways, more advanced that Emacs. However, I have always struggled to use Emacs, and it bothered me. Why can I not use the text editor most used by coders I respect? After some perseverance, I found how to set up things like CUA-style editing, and felt much more comfortable. Another post here describes a few of the things I learned that helped.

To provide a uniform experience on the three platforms, I decided to write a configuration file that would be run by the .emacs file. This file, called dot-emacs.el, would set up all my preferences, with machine-specific things like paths being handled programatically based upon the machine’s hostname. For example:

;; Where is CLISP?
(defun clisp-location ()  "Get loc. for CLISP on host"
    (cond
        ((equal system-name hostname1)
            "/sw/bin/clisp")
        ((equal system-name hostname2)
            "/usr/bin/clisp")
        ("/usr/bin/clisp"))) ;; Default to sensible value

This is a function that tests the hostname of the computer via the system-name variable (defined by Emacs rather than me), and then returns the correct path to CLISP for the host the code is running on. This code is then used as follows to actually specify where CLISP is:

(setq inferior-lisp-program (clisp-location))

In addition to specifying paths, we need to use edit modes to make editing specific types of file more convenient. Instead of installing these into the site-lisp directory, I store them in another directory (along with dot-emacs.el). In dot-emacs.el, I add this directory to the load path using the following code:

(setq load-path (cons
    (expand-file-name (this-path-on-host))
    load-path))

where this-path-on-host is a function that returns the directory where dot-emacs.el is on the current host.

So that changes made to dot-emacs.el on one host can easily be mirrored to the other hosts, I store dot-emacs.el and the edit mode files under the control of CVS. This allows me to have a uniform environment, regardless of computer, and move to other computers in the future, if needed.