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

The defaults are horrible for this. However, you can extend Emacs to work like SlickEdit and TextMate, that is, copy/cut the current line when no text is selected:

(transient-mark-mode t)
(defadvice kill-ring-save (before slick-copy activate compile)
  "When called interactively with no active region, copy a single line instead."
  (interactive
   (if mark-active (list (region-beginning) (region-end))
     (message "Copied line")
     (list (line-beginning-position)
           (line-beginning-position 2)))))
(defadvice kill-region (before slick-cut activate compile)
  "When called interactively with no active region, kill a single line instead."
  (interactive
   (if mark-active (list (region-beginning) (region-end))
     (list (line-beginning-position)
           (line-beginning-position 2)))))

Place the above in .emacs. Then, to copy a line, M-w. To delete a line, C-w. To duplicate a line, C-a M-w C-y C-y C-y ....