Emacs comment/uncomment current line

Question

I know there's already an Emacs question on this, and that it was closed, but I find it quite relevant and important.

Basically, I want to comment/uncomment the current line. I was expecting this to be fairly easy with a macro, but I found that it really isn't.

If the current line is commented, uncomment. If it is uncommented, comment it. And I would also to comment out the whole line, not just from cursor position.

I tried a macro like this:

C-a

'comment-dwim

But this only work to comment a line, not to uncomment it, if it's already commented.

I'm not sure of how easy it is, but if there's some way, I'd really like it.

Also, the reason I love this idea so much is that when I used Geany, I just used C-e and it was perfect.

Answer 1

Trey's function works perfectly, but it isn't very flexible.

Try this instead:

(defun comment-or-uncomment-region-or-line ()
    "Comments or uncomments the region or the current line if there's no active region."
    (interactive)
    (let (beg end)
        (if (region-active-p)
            (setq beg (region-beginning) end (region-end))
            (setq beg (line-beginning-position) end (line-end-position)))
        (comment-or-uncomment-region beg end)))

It comments/uncomments the current line or the region if one is active.

---

If you prefer, you can modify the function to jump to the next line after (un)commenting the current line like this:

(defun comment-or-uncomment-region-or-line ()
    "Comments or uncomments the region or the current line if there's no active region."
    (interactive)
    (let (beg end)
        (if (region-active-p)
            (setq beg (region-beginning) end (region-end))
            (setq beg (line-beginning-position) end (line-end-position)))
        (comment-or-uncomment-region beg end)
        (next-line)))

Note that only thing that's changed is the added next-line command at the end of the function.