How to enter Erlang Mode in Emacs?

Question

How do I enter erlang mode in emacs to get code highlighting, etc.? Whenever I open an erlang file nothing special happens. Do I need to change something in my .emacs file, or do I need to add a module to emacs, or something else?

Answer 1

Emacs doesn't come with an Erlang mode, so you need to add one. Erlang itself appears to ship with an Emacs mode that you can use; there are instructions on installing it and using it on their website, but it comes down to just adding their folders to your load path and exec path, setting a variable, and requiring the module:

(setq load-path (cons  "/usr/local/otp/lib/tools-<ToolsVer>/emacs" load-path))
(setq erlang-root-dir "/usr/local/otp")
(setq exec-path (cons "/usr/local/otp/bin" exec-path))
(require 'erlang-start)

The paths might be different depending on where you installed Erlang

Answer 2

As of 22 March 2013, the Erlang mode is installable through the MELPA package archive. If you haven't done so already, activate MELPA by putting the following in your .emacs:

(add-to-list 'package-archives
  '("melpa" . "http://melpa.milkbox.net/packages/") t)

Then hit M-x list-packages and install the erlang package.