How can I remap Ctrl-backspace in Emacs? - emacs

I'm trying to map Ctrl-backpace to `kill-whole-line in emacs but no such luck.
I've tried:
(global-set-key (kbd "C-\d") 'kill-whole-line)
and
(global-set-key "\C-\d") 'kill-whole-line)
but they have either given me Lisp errors or just plain don't work.
Maybe my syntax is wrong?
Thanks,
-Adam

Try this:
(global-set-key [C-backspace] 'kill-whole-line)

Related

Is it possible to collapse a function in emacs?

So, for a lisp homework assignment I have, it has a long defparameter expression that's a large data set. What I'm wondering is, does emacs or SLIME have anything to "collapse" that large defparameter into a single line, like, say, MATLAB does?
Like Bertfred mentioned, hideshow works great, and it comes build in with more recent versions of emacs. To use it simply add the following snippet to your init file:
(add-hook 'prog-mode-hook #'hs-minor-mode)
(global-set-key (kbd "C-c <right>") 'hs-show-block)
(global-set-key (kbd "C-c <left>") 'hs-hide-block)
The first line enables the functionality in any major mode associated with programming. Once there, C-c <left> and C-c <right> should do what you expect - just be mindful of where point is.
https://www.emacswiki.org/emacs/HideShow
There's also a package on Melpa called vimish-fold (or the equivalent evil version of it - evil-vimish-fold).
It is not as "automatic" as hideshow or outline in the sense that you have to select the lines you want to fold, but the advantage is that you can fold any lines. And the folds don't disappear the when you close your file.
You can define your keybindings for creating/deleting folds and for unfolding/refolding folds, and there you go!
(global-set-key (kbd "your-keybinding") 'vimish-fold)
(global-set-key (kbd "your-keybinding") 'vimish-fold-delete)
(global-set-key (kbd "your-keybinding") 'vimish-fold-toggle)

Emacs weird behaviour with key

I'm a Vim user, and I decided to give Emacs a try.
Now I get a weird problem with Emacs. I installed the Evil mode, which is awesome.
In my .emacs I have the follow setting:
(define-key evil-motion-state-map "\C-u" 'scroll-up-command)
This works well.
But what if I wanted to change it to spacebar or Return key?
(define-key evil-motion-state-map "<return>" 'scroll-up-command)
(define-key evil-motion-state-map "SPC" 'scroll-up-command)
Nothing spectular will happen, the return/Enter key and spacebar are behaving their standard behaviour. I looked around for the right keys, and it seems they're the rights keys. For example,
(global-set-key (kbd "<return>") 'save-buffer)
Works fine.
What am I doing wrong in Emacs/Evil with the Enter key?
Use (kbd "<return>"), not "<return>". Likewise, (kbd "SPC").
You probably want (kbd "RET"), not (kbd "<return>").
Binding C-u, as you did at first, is a bad idea. You do not want to do that, ever. Just use C-u as it was intended, for command universal-argument -- see the Emacs manual, node Arguments.

Binding C-; in Emacs

How can I bind a function to C-; in Emacs? I tried to use bracket notation with an escape character:
(global-set-key [C-\;] 'my-func)
and kbd:
(global-set-key (kbd "<C-;>") 'my-func)
Is it not possible? If so, then why acknowledge the existence of the chord (C-; is undefined)?
I am running Emacs 24.1.1.
(global-set-key (kbd "C-;") 'my-func) seems to avoid problems with the comment character and escaping.

Emacs: why does keybinding with M-S-[letter] set mark?

I'm experimenting with new bindings for basic movement in Emacs. Borrowing from this page and ErgoEmacs, this remapping works as expected:
(global-set-key (kbd "M-i") 'previous-line)
(global-set-key (kbd "M-k") 'next-line)
(global-set-key (kbd "M-j") 'backward-char)
(global-set-key (kbd "M-l") 'forward-char)
But defining a Shift-Alt combination gives an unwanted side-effect.
(global-set-key (kbd "M-I") 'cua-scroll-down)
(global-set-key (kbd "M-K") 'cua-scroll-up)
(global-set-key (kbd "M-J") 'backward-word)
(global-set-key (kbd "M-L") 'forward-word)
Running describe-key (C-h k) shows that the bindings were successful. And these bindings move point as they should, but for some reason it sets the mark at my original position, and gives me a highlighted region as I move the point.
How do I correct this?
EDIT:
This has something to do with cua-mode. When I disable cua-mode, the problem disappears. Unfortunately, disabling cua-mode is not a desirable solution.
EDIT:
This is a bug in Emacs. It's tracked as bug#11221, title 'cua-mode activates the mark for shifted bindings'. From the discussion on the mailing list, it sounds like there will be a fix to cua-base.el.
It's indeed likely triggered by shift-select-mode, but it looks like a bug: shift-select-mode should pay attention to the fact that the command is bound to a shifted key. Try to reproduce the problem without using CUA and then please report it with M-x report-emacs-bug.
That's because of the shift selection. You can disable it by setting shift-select-mode to nil.

Binding M-<up> / M-<down> in Emacs 23.1.1

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.
Using a global key binding, I can get it to work with letter combinations, like (kbd "M-m"), but every combination I have tried for the arrow keys just gives me a message that doesn't make sense, I always get:
"ESC <up> is undefined"
What I have tried:
(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
From the comments:
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.
Thanks for the suggestions, but they all turned out the same.
Emacs has a complex mechanism to handle the vicissitudes of function key and modifier encodings on various terminal types. It doesn't work out of the box in all cases. The following settings should work on your terminal:
(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)
You should be able to use (kbd "<M-up>") and (kbd "<M-down>") in place of [(meta up)] and [(meta down)], as long as you've done the step of telling Emacs (via input-decode-map) about the escape sequences that your terminal uses to encode these key combinations.
I always use C-h k (key) (i.e. describe-key) to find out how Emacs refers to (key), and then use (kbd) with that same string to utilise it.
In this case, describe-key returns <M-up>, so I would use (global-set-key (kbd "<M-up>") 'transpose-line-up) (exactly as J.F. Sebastian has done).
Edit:
Running emacs -nw (but not through screen), describe-key reports ESC <up> (translated from ESC M-[ A), and (kbd "ESC <up>") is successful for binding it.
Running screen emacs -nw, describe-key reports ESC <up> (translated from ESC M-O A), which seems to match what you see, and the binding for (kbd "ESC <up>") still works for me.
(n.b. Tested under Cygwin with screen 4.00.03, and Emacs 23.2.1.)
(global-set-key [M-up] 'beginning-of-buffer)
(global-set-key [M-down] 'end-of-buffer)
In my OSX, I have this definition to perform Alt-up/down to jump to top/bottom of buffer.
ugly workaround:
I've typed C-q <M-up> it produced ^[[1;3A on the terminal inside screen inside emacs.
(global-set-key (kbd "<M-up>") 'transpose-line-up)
(global-set-key (kbd "^[[1;3A") 'transpose-line-up)
I've got Lisp error: (void-function transpose-line-up) so the key bindings work.
Note: C-q runs the command quoted-insert.
The following lines work for me on macOS 10.11.6 and GNU Emacs 25.2.1:
(global-set-key (kbd "ESC <down>") 'end-of-buffer)
(global-set-key (kbd "ESC <up>") 'beginning-of-buffer)
Assuming you have the functions transpose-line-up and transpose-line-down already defined (as it seems to be from the example code in your original question):
(global-set-key [(meta up)] 'transpose-line-up)
(global-set-key [(meta down)] 'transpose-line-down)
works on OSX Terminal:
(global-set-key (kbd "ESC <up>") 'transpose-line-up)
(global-set-key (kbd "ESC <down>") 'transpose-line-down)