Hiding ^M in emacs

Question

Sometimes I need to read log files that have ^M (control-M) in the line endings. I can do a global replace to get rid of them, but then something more is logged to the log

Answer 1

If you'd like to view the log files and simply hide the ^M's rather than actually replace them you can use Drew Adam's highlight extension to do so.

You can either write elisp code or make a keyboard macro to do the following

select the whole buffer
hlt-highlight-regexp-region
C-q C-M
hlt-hide-default-face

This will first highlight the ^M's and then hide them. If you want them back use `hlt-show-default-face'

Answer 2

You can change the display-table entry of the Control-M (^M) character, to make it displayable as whitespace or even disappear totally (vacuous). See the code in library pp-c-l.el (Pretty Control-L) for inspiration. It displays ^L chars in an arbitrary way.

Edited: Oops, I just noticed that @binOr already mentioned this method.

Answer 3

what about using dos2unix, unix2dos (now tofrodos)?

Answer 4

If you encounter ^Ms in received mail in Gnus, you can use W c (wash CRs), or

(setq gnus-treat-strip-cr t)

Answer 5

Edric's answer should get more attention. Johan Bockgård's solution does address the poster's complaint, insofar as it makes the ^M's invisible, but that just masks the underlying problem, and encourages further mixing of Unix and DOS line-endings.

The proper solution would be to do a global M-x replace-regexp to turn all line endings to DOS ones (or Unix, as the case may be). Then close and reopen the file (not sure if M-x revert-buffer would be enough) and the ^M's will either all be invisible, or all be gone.

Answer 6

sudeepdino008's answer did not work for me (I could not comment on his answer, so I had to add my own answer.).

I was able to fix it using this code:

(defun dos2unix ()
  "Replace DOS eolns CR LF with Unix eolns CR"
  (interactive)
    (goto-char (point-min))
      (while (search-forward (string ?\C-m) nil t) (replace-match "")))