On InternetRelayChat, you sometimes quote stuff from other sources that include linebreaks. This function removes all linebreaks in the current “paragraph” – that is, until the next empty line or until the end of the buffer. (But read on for alternative solutions.)

    (defun unwrap-line ()
      "Remove all newlines until we get to two consecutive ones.
    Or until we reach the end of the buffer.
    Great for unwrapping quotes before sending them on IRC."
      (let ((start (point))
            (end (copy-marker (or (search-forward "\n\n" nil t)
            (fill-column (point-max)))
        (fill-region start end)
        (goto-char end)
        (goto-char start)))

And here is how to replace the useless binding for fill-paragraph in ERC:

    (define-key erc-mode-map (kbd "M-q") 'unwrap-line)

See also UnfillParagraph.

There also exist some unwrapping utilities, the functions pstxt-x-unfill-* in pstxt.el, at http://www.gnufans.net/~deego/pub/emacspub/lisp-mine/pstxt/. Those functions simply setq fill-column to a large number and then fill. This also means that they get to use emacs’ fill-region functions among others, which means that will take care of removing double spaces etc. :) – DeepakGoel

Hmm, I couldn’t get that working. But now I see you’re using it for other sources. Here’s something I wrote which will unfill all newlines waiting to be sent. Good for copying other people’s lines in other erc buffers, too.

  ;; helper defun to unfill lines that have been cut from elsewhere
  (defun erc-unfill ()
    "Unfill the region after the prompt. Intended to be called just before you
    send a line"
      (goto-char (previous-single-property-change (point) 'erc-prompt))
      (while (search-forward "\n" nil t)
        (delete-backward-char 1)

Good idea to bind it to M-q. – DamienElmes

For interactive use, it is convenient to call M-^ (‘delete-indentation’), which merges the current line with the one preceding it. – ChongYidong

CategoryChatClient CategoryFilling