(require 'w3m)

(defvar rtm-feed-url-prefix "https://www.rememberthemilk.com/atom/")
(defvar rtm-feed-content-type "application/atom+xml")
(defvar rtm-temporary-file-prefix "/tmp/rtm")
(defvar rtm-convert-program "/home/tabe/bin/rtm2howm.scm")

(defun rtm-retrieve (user)
  (interactive "sUser: ")
  (catch 'failed
    (let ((temp-file (make-temp-file rtm-temporary-file-prefix)))
      (unwind-protect
          (progn
            (set-file-modes temp-file ?\600)
            (with-temp-file temp-file
              (let ((content-type (w3m-retrieve (concat rtm-feed-url-prefix user "/") nil t)))
                (unless (equal rtm-feed-content-type content-type)
                  (throw 'failed (message "failed.")))))
            (call-process rtm-convert-program temp-file t t))
        (delete-file temp-file)
        ))))