display in the mode-line the number of characters in the selection

Question

I'm used to have display of the number of selected characters in the mode line when there is an active selection (in vim).

Is it possible to achieve this in emacs?

I managed to display the column index besides the line index, which is something... But not quite enough. I also looked at the mode line format documentation, but without success.

I also found smart mode line but I think that it doesn't offer the feature as of now.

Answer 1

Use library Mode-Line Position (modeline-posn.el).

It shows you the size of the selection (active region) in the mode line, using the region face. It optionally tells you also the number of selected characters or characters and lines, etc.

Answer 2

The following code could be a good start for you.

(setq mode-line-format '("%e" (:eval (number-to-string (abs (- (point) (mark)))))))

This sets the mode line to display the number of selected characters. It only updates after some events, e.g. C-l.

To finish this off you'd just want to add the specified form to an existing mode-line-format variable.

Answer 3

I ended up making my own function, I will leave it here in case anyone is interested in the future:

(defun mode-line-region-chars (prefix middle subfix)
  (if (use-region-p)
      (let ((characters (abs (- (region-end) (region-beginning))))
            (lines (abs (- (line-number-at-pos (region-end))
                           (line-number-at-pos (region-beginning))))))
        (concat prefix
                (number-to-string characters)
                (if (> lines 0)
                    (concat middle (number-to-string lines)))
                subfix))))

If you have selected 51 characters across 4 lines, and the arguments are "(Characters: ", " Lines: ", ")", it will return "(Characters: 51 Lines: 4)".