How may I call untabify against a rectangular region?

This screenshot illustrates what I am trying to accomplish. I have a messy mixture of tabs and spaces in the region I have circled. untabify will fix it, but I don't want to eliminate the tabs on the left of each line. Those are fine.

enter image description here

  • 1
    Can you elaborate? For instance, you could show an example, and what you'd expect as the result.
    – user12563
    Jun 4, 2019 at 20:27
  • @DoMiNeLa10, done.
    – daveloyall
    Jun 5, 2019 at 15:17

1 Answer 1


The builtin untabify command doesn't support the rectangular region. Here is a new command:

(defun my-untabify (b e)
  "Like `untabify' but support both ordinary and rectangular region."
  (interactive "*r")
  (if (region-noncontiguous-p)
       (lambda (startcol endcol)
         (untabify (progn (move-to-column startcol) (point))
                   (progn (move-to-column endcol) (point))))
       b e)
    (untabify b e current-prefix-arg)))
  • You could contribute your code to Emacs (even better, using region-boundaries so it can even work on non-rectangular non-contiguous regions).
    – Stefan
    Jun 4, 2019 at 21:15
  • @Stefan How to create a non-rectangular non-contiguous region as a user? Any other emacs commands support such region? In Emacs 26.2, region-bounds is called only two times.
    – xuchunyang
    Jun 5, 2019 at 3:22
  • region-bounds is new. User-level commands to create a non-contiguous region are still waiting for someone to implement them (presumably the zones.el package in GNU ELPA could be a good starting point).
    – Stefan
    Jun 5, 2019 at 14:02
  • I finally got around to testing this and LGTM. I'll now go search around to find out how to replace a builtin. Incidentally, I was not aware of the difference between C-SPC and C-x SPC until today. (all the rectangle command I'd tried so far work with regular regions, except the visuals don't match.)
    – daveloyall
    Jun 13, 2019 at 16:46

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