Re: easiest way to subscribe to 10 groups at once

[Ted Zlatanov <tzz@lifelogs.com>]

On Tue, 07 Oct 2008 08:27:35 +0800 jidanni@jidanni.org wrote: 

j> This step was easy enough:
j> # xargs -n 1 noffle -s < additional_groups_I_want_to_subscribe_to
j> Next I attempted to use
j> F runs the command gnus-group-find-new-groups
j> which merely chomped CPU and made a giant buffer in the buffer list,
j> until I hit ^G. No wonder F is disabled.
j> (As I don't use .newsrc, I didn't investigate importing from there.)
j> OK, then I did
j> # perl -nlwe 'print "(gnus-group-jump-to-group \"$_\")"' < additional_groups...
j> (gnus-group-jump-to-group "gmane.comp.handhelds.openmoko.announce")
j> (gnus-group-jump-to-group "gmane.comp.handhelds.openmoko.apps")
j> (gnus-group-jump-to-group "gmane.comp.handhelds.openmoko.buglog")...
j> Which I pasted into the minibuffer of
j> M-: (translated from <escape> :) runs the command eval-expression
j> whereupon I was finally able to use uuuuu... to subscribe them. Jeez.

It seems useful to have a "mapfile" function similar to mapcar which
would feed every line from a file into a list and then mapcar on the
list.  Something like this:

(defun file-to-list (file)
  "Get contents of FILE as a list of nonempty strings.
Blank lines are skipped."
  (with-temp-buffer
    (let ((list))
      (insert-file-contents file)
      (while (not (eobp))
	(let ((line (buffer-substring (line-beginning-position) (line-end-position))))
	  (when (< 0 (length line))
	    (push line list)))
	(forward-line))
      list)))

(defun mapfile (function file)
  (mapcar function (file-to-list file)))

(mapfile 'insert "/etc/hosts") ; side effect--insert every line as a string

I don't know if my version is optimal (for large files it's definitely
not), but it seems generally a very useful idea.

Ted