在 Emacs 23.1.1 中绑定 M- / M-

I'm trying to put in a feature that I miss from Eclipse, where Alt+[Up/Down] transposes the lines up or down, but can not for the life of me figure out how to assign to these keys properly. I am using it in -nw mode (so just in a shell window), and typically run in a screen session.

使用全局键绑定，我可以让它与字母组合一起使用，例如(kbd "M-m")，但是我尝试过的方向键组合只会给我一条没有意义的消息，我总是得到：

"ESC <up> is undefined"

我尝试过的：

(global-set-key (kbd "M-<up>") 'transpose-line-up)    
(global-set-key (kbd "<escape>-<up>") 'transpose-line-up)
(global-set-key [M-up] 'transpose-line-up)
(global-set-key [\e \M-O A] 'transpose-line-up)

And C-h c just returns:

ESC <up> (translated from ESC M-O A) is undefined

None of these work, either using ESC or Alt.

Any idea how I can make this work? I would prefer to have these as Alt+[Up/Down] just because that is what I am used to.

Edit

来自评论：

• C-q Up prints ^[OA.

• C-q M-Up prints ^[ and moves the cursor up a line.

• C-h k (Alt+Up) prints ESC <up> (translated from ESC M-O A) is undefined.

感谢您的建议，但结果都是一样的。

Emacs 有一个复杂机制处理各种终端类型上功能键和修饰符编码的变化。它并非在所有情况下都能开箱即用。以下设置应该适用于您的终端：

(define-key input-decode-map "\e\eOA" [(meta up)])
(define-key input-decode-map "\e\eOB" [(meta down)])
(global-set-key [(meta up)] 'transpose-line-up)
(global-set-key [(meta down)] 'transpose-line-down)

你应该能够使用(kbd "<M-up>") and (kbd "<M-down>")代替[(meta up)] and [(meta down)]，只要你完成了告诉 Emacs 的步骤（通过input-decode-map）有关您的终端用于对这些组合键进行编码的转义序列。