Elisp function calling to Ruby for escape and unescape HTML

escape-unescape-html.el

(defun escape-html (start end)
  (interactive "r")
  (if (use-region-p)
      (let ((regionp (buffer-substring start end)))
	(delete-region start end)
	(call-process-region regionp nil "ruby" nil t nil "-e" "# encoding: utf-8
require 'cgi'
print CGI.escapeHTML(ARGF.read)"))))

(defun unescape-html (start end)
  (interactive "r")
  (if (use-region-p)
      (let ((regionp (buffer-substring start end)))
	(delete-region start end)
	(call-process-region regionp nil "ruby" nil t nil "-e" "# encoding: utf-8
require 'cgi'
print CGI.unescapeHTML(ARGF.read)"))))