gistfile1.el

(defun gbj-backup-shell (&optional arg)
  "makes a copy of the current shell with timestamp appended to the filename"
  (interactive)
  (let* 
      (
       (save-dir "~/build/shells/")
       (orig-file arg)
       (mod-str nil)
      )
    (if (not orig-file)
	(setq orig-file (concat save-dir (buffer-name))))
    (with-temp-buffer
					; get the time stamp
      (insert (current-time-string)) 

					;fix up the bad chars
      (goto-char (point-min))
      (while (re-search-forward "[ :]" nil t)
	(replace-match "-" nil nil))
      (goto-char (point-min))
      (while (re-search-forward "--" nil t)
	(replace-match "-" nil nil))
      (setq mod-str (buffer-string)))
					; copy out the file
    (write-file  (concat orig-file "." (substring mod-str 4 )))
    (rename-buffer (file-name-nondirectory orig-file))
    (setq buffer-file-name nil)
    (auto-save-mode -1)
    (message (format "Wrote out %s" (concat orig-file "." (substring mod-str 4 ))))
      
    )
  )