Set xattr after saving UTF-8 files in Emacs

gistfile1.el

(when (eq system-type 'darwin)
  (defvar my-set-xattr-utf-8-modes '(text-mode org-mode ruby-mode js2-mode css-mode))
  (defun my-set-xattr-if-utf-8()
    (when (and (memq major-mode my-set-xattr-utf-8-modes)
               (string-match "^utf-8" (prin1-to-string buffer-file-coding-system)))
      (call-process "xattr" nil 0 nil "-w" "com.apple.TextEncoding" "UTF-8;134217984" buffer-file-name)))
  (add-hook 'after-save-hook 'my-set-xattr-if-utf-8))