Disable auto-fill-mode locally (or un fill-paragraph) with emacs.

Question

I use M-q for fill-paragraph, can I do the un-fill-paragraph in auto-fill-mode?

With org mode, I sometimes enter [[Very long HTML][Name with spaces]], and for the 'Name with spaces' the auto-fill mode break the whole line based on the inserted space, which makes it very ugly.

Is there a command something like un-fill-paragraph? Or, is there a way disable auto-fill-mode temporarily/locally?

Answer 1

Emacs does not record what was your line before calling fill-paragraph. So the only thing you can do is C-_ which runs the command undo. It can undo your fill-paragraph command but only if it is the preceding command call.

If you want to put a multi-line paragraph on one line you could do like this :

• Select the region
• C-M-% C-q C-j RET SPACE RET !

Answer 2

I use the following snippet to fill and un-fill paragraphs (using only M-q), it is really, really handy. I borrowed it from Xah Lee, but removed some comments and whitespace in order to make it fit in here. The link in the first comment goes to his original code.

;; http://xahlee.org/emacs/modernization_fill-paragraph.html
(defun compact-uncompact-block ()
  "Remove or add line endings on the current block of text.
This is similar to a toggle for fill-paragraph and unfill-paragraph
When there is a text selection, act on the region.

When in text mode, a paragraph is considered a block. When in programing
language mode, the block defined by between empty lines.

Todo: The programing language behavior is currently not done.
Right now, the code uses fill* functions, so does not work or work well
in programing lang modes. A proper implementation to compact is replacing
newline chars by space when the newline char is not inside string.
"
  (interactive)
  (let (bds currentLineCharCount currentStateIsCompact
            (bigFillColumnVal 4333999) (deactivate-mark nil))
    (save-excursion
      (setq currentLineCharCount
            (progn
              (setq bds (bounds-of-thing-at-point 'line))
              (length (buffer-substring-no-properties (car bds) (cdr bds)))))
      (setq currentStateIsCompact
            (if (eq last-command this-command)
                (get this-command 'stateIsCompact-p)
              (if (> currentLineCharCount fill-column) t nil)))
      (if (and transient-mark-mode mark-active)
          (if currentStateIsCompact
              (fill-region (region-beginning) (region-end))
            (let ((fill-column bigFillColumnVal))
              (fill-region (region-beginning) (region-end)))
            )
        (if currentStateIsCompact
            (fill-paragraph nil)
          (let ((fill-column bigFillColumnVal))
            (fill-paragraph nil))))
      (put this-command 'stateIsCompact-p
           (if currentStateIsCompact
               nil t)))))
(global-set-key (kbd "M-q") 'compact-uncompact-block)