emacs24 backtab未定义，如何定义此快捷键

Question

如何在emacs24中定义<backtab>短键？

我找到了一些解决方案，

像：

• http://stuff.mit.edu/afs/sipb/user/daveg/Info/backtab-howto.txt
• Emacs Shift-Tab to left shift the block

但它对我不起作用。

---

最后：

(global-set-key (kbd "<backtab>") 'un-indent-by-removing-4-spaces)
(defun un-indent-by-removing-4-spaces ()
  "remove 4 spaces from beginning of of line"
  (interactive)
  (save-excursion
    (save-match-data
      (beginning-of-line)
      ;; get rid of tabs at beginning of line
      (when (looking-at "^\\s-+")
        (untabify (match-beginning 0) (match-end 0)))
      (when (looking-at "^    ")
        (replace-match "")))))

为我工作 !!!

感谢@Drew和@lawlist。