How do I duplicate a whole line in Emacs?

Question

I saw this same question for VIM and it has been something that I myself wanted to know how to do for Emacs. In ReSharper I use CTRL-D for this action. What is the least num

Answer 1

In addition to the previous answers you can also define your own function to duplicate a line. For example, putting the following in your .emacs file will make C-d duplicate the current line.

(defun duplicate-line()
  (interactive)
  (move-beginning-of-line 1)
  (kill-line)
  (yank)
  (open-line 1)
  (next-line 1)
  (yank)
)
(global-set-key (kbd "C-d") 'duplicate-line)

Answer 2

;; http://www.emacswiki.org/emacs/WholeLineOrRegion#toc2
;; cut, copy, yank
(defadvice kill-ring-save (around slick-copy activate)
  "When called interactively with no active region, copy a single line instead."
  (if (or (use-region-p) (not (called-interactively-p)))
      ad-do-it
    (kill-new (buffer-substring (line-beginning-position)
                                (line-beginning-position 2))
              nil '(yank-line))
    (message "Copied line")))
(defadvice kill-region (around slick-copy activate)
  "When called interactively with no active region, kill a single line instead."
  (if (or (use-region-p) (not (called-interactively-p)))
      ad-do-it
    (kill-new (filter-buffer-substring (line-beginning-position)
                                       (line-beginning-position 2) t)
              nil '(yank-line))))
(defun yank-line (string)
  "Insert STRING above the current line."
  (beginning-of-line)
  (unless (= (elt string (1- (length string))) ?\n)
    (save-excursion (insert "\n")))
  (insert string))

(global-set-key (kbd "<f2>") 'kill-region)    ; cut.
(global-set-key (kbd "<f3>") 'kill-ring-save) ; copy.
(global-set-key (kbd "<f4>") 'yank)           ; paste.

add the elisp above to you init.el, and you get cut/copy whole line function now, then you can F3 F4 to duplicate a line.

Answer 3

Instead of kill-line (C-k) as in C-a C-k C-k C-y C-y use the kill-whole-line command:

C-S-Backspace
C-y
C-y

The advantages over C-k include that it does not matter where point is on the line (unlike C-k which requires being at start of the line) and it also kills the newline (again something C-k does not do).

Answer 4

Place cursor on line, if not at beginning do a CTRL-A, then:

CTRL-K

CTRL-K

CTRL-Y

CTRL-Y

Answer 5

ctrl-k, ctrl-k, (position to new location) ctrl-y

Add a ctrl-a if you're not starting at the beginning of the line. And the 2nd ctrl-k is to grab the newline character. It can be removed if you just want the text.

Answer 6

The simplest way is Chris Conway's method.

C-a C-SPACE C-n M-w C-y

That's the default way mandated by EMACS. In my opinion, it's better to use the standard. I am always careful towards customization one's own key-binding in EMACS. EMACS is already powerful enough, I think we should try our best to adapt to its own key-bindings.

Though it's a bit lengthy, but when you are used to it, you can do fast and will find this is fun!