Indent Clojure code with Emacs

check-clojure-mode-version.el

;;; File: check-clojure-mode-version
;;; Matthew Darling
;;; 15 June 2016

(setq package-archives '(("gnu" . "http://elpa.gnu.org/packages/")
                         ("melpa-stable" . "http://stable.melpa.org/packages/")))
(require 'package)
(package-initialize)
(package-refresh-contents)

(defun apu--package-up-to-date-p (package)
  "Borrowed from auto-package-update: https://github.com/rranelli/auto-package-update.el/blob/cdef79f9fc6f8347fdd05664978fb9a948ea0410/auto-package-update.el#L226"
  (when (and (package-installed-p package)
             (cadr (assq package package-archive-contents)))
    (let* ((newest-desc (cadr (assq package package-archive-contents)))
           (installed-desc (cadr (or (assq package package-alist)
                                     (assq package package--builtins))))
           (newest-version  (package-desc-version newest-desc))
           (installed-version (package-desc-version installed-desc)))
      (version-list-<= newest-version installed-version))))

(defun clojure-mode-up-to-date-p ()
  "Check if clojure-mode is the latest version."
  (apu--package-up-to-date-p 'clojure-mode))

(defun die-if-outdated-clojure-mode ()
  (when (not (clojure-mode-up-to-date-p))
    (message "clojure-mode is out of date! Please boot up Emacs separately and update it with M-x package-install clojure-mode")
    (kill-emacs -1)))

clj-indent.sh

#!/bin/sh
# File: clj-indent
# Opens the first argument in emacs and executes the
# emacs-format-function based on clojure-mode

## originally from: http://www.cslab.pepperdine.edu/warford/BatchIndentationEmacs.html
## note: compared to the version on that web page, this version only
## handles one file because, when used with find, everything else is
## unnecessary

echo "Indenting $1 with emacs in batch mode"
/Applications/Emacs.app/Contents/MacOS/Emacs -batch $1 \
                                             # load this specific file
                                             -l ~/bin/emacs-format-file \
                                             # run this specific function
                                             -f "emacs-format-function"

emacs-format-file.el

;;; File: emacs-format-file
;;; Stan Warford
;;; 17 May 2006
;;; from http://www.cslab.pepperdine.edu/warford/BatchIndentationEmacs.html

(require 'package)
(package-initialize)

(defun emacs-format-function ()
  "Format the whole buffer."
  (when (or (string-suffix-p ".clj" (buffer-name))
            (string-suffix-p ".edn" (buffer-name)))
    (clojure-mode))
  (indent-region (point-min) (point-max) nil)
  (untabify (point-min) (point-max))
  (save-buffer))

indent-in-directory.sh

#!/bin/sh
# File: indent-in-directory

echo "Checking for newer versions of packages"
/Applications/Emacs.app/Contents/MacOS/Emacs -batch $1 \
                                             # load this specific file
                                             -l ~/bin/check-clojure-mode-version.el \
                                             # run this specific function
                                             -f "die-if-outdated-clojure-mode" \
                                             # redirect stderr to nowhere
                                             2> /dev/null &&
    echo "Indenting all .clj and .edn files in" $(pwd) &&
    # find files in the current directory ending with .clj or .edn
    find . -type f \( -name "*.clj" -o -name "*.edn" \) \
         # execute this shell script, where {} represents a particular file that is found
         -exec ~/bin/clj-indent.sh {} \; \
         # redirect stderr to nowhere
         2> /dev/null

Checking the file extensions shouldn't even be needed, but it seemed like the auto-mode-alist wasn't being populated. Or it wasn't being respected. Anyway, that's why the manual call to (clojure-mode) is there, and the file extension checking elsewhere.

Otherwise, this could be totally generic and indent any kind of file as needed! Which would be neat.