Re: Backing up expired mail?

[Lars Magne Ingebrigtsen <larsi@gnus.org>]

Steinar Bang <sb@metis.no> writes:

> > I'd suggest doing this from inside Gnus.  Write a macro to enter the
> > group, process-mark all the articles and `B m' them to somewhere
> > else.
> 
> Hm... is this a keyboard macro, or a lisp macro? (I've never quite
> understood lisp macros...).

Keyboard macro.

> What would be the best/simplest way to gzip the articles, after I've
> moved them?

Hm...  I think the easiest would be to do it from a shell, but you can
also do some mapcar'ing on the output from `directory-files'.  Perhaps
there should be a function to do this; it's not uncommon that one
wants to do something like this.

  (shell-map-directory-files "~/some/dir/" "gzip" "^[0-9]+$")

to run gzip on all files that match that regexp.

Howzabout this:

(defun shell-map-directory-files (directory program &optional regularp match)
  "Execute PROGRAM on all the files in DIRECTORY.
If REGULARP (the prefix), only use the files that are regular files.
If MATCH, only use the files that match this regexp.

If PROGRAM contains the string \"%s\", insert each file name to be
processed there.  For instance:

   \(shell-map-directory-files \"~/smallfiles\" \"cat %s >> /tmp/bigfile\" t)

The number of files processed will be returned."
  (interactive "DDirectory: \nsProgram: \nP")
  (let ((format (if (string-match "%s" program) 'format 'concat)))
    (length
     (mapcar
      (lambda (file)
	(call-process shell-file-name nil nil nil shell-command-switch
		      (funcall format program file)))
      (directory-files directory t match)))))

If this seems useful, I'll mail it to RMS and see whether it can be
included in Emacs.

-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen