Re: understanding emacs packages

[Joel J. Adamson]

knubee <knubee@gmail.com> writes:

> When I upgrade my gnu/linux distribution and re-install various emacs
> applications, it is not always clear to me what is the cause of an
> error when I run an emacs application. As an example, there may be
> some oddness inserting dates in org-mode. No errors, but failure to do
> things.

Why are you re-installing lisp packages?  They should all still be
there in your site-packages directory.  On Slackware 12.0 with Emacs
23, under /usr/share/emacs I have
  /usr/share/emacs:
  total used in directory 10 available 1010628
  drwxr-xr-x   7 root root  176 2007-09-23 00:05 .
  drwxr-xr-x 193 root root 5200 2006-03-25 19:29 ..
  drwxr-xr-x   5 root root  120 2007-09-24 10:24 21.4
  drwxr-xr-x   3 root root   72 2007-09-24 10:59 22.1
  drwxr-xr-x   6 root root  152 2007-09-23 00:05 23.0.0
  drwxr-xr-x   3 root root   72 2007-05-03 16:01 etc
  drwxr-xr-x   6 root root 4608 2007-09-23 00:05 site-lisp

I should get rid of the 21.4 and 22.1 directories...all the
"third-party" packages are in site-lisp.  No reinstalling necessary.

> This could be because the gnu/linux distro is still in beta (e.g.,
> ubuntu gutsy), it could be because I have  not installed all the
> necessary emacs packages, or it could be because there non-emacs code/
> application that is necessary.

What feature of your Linux distro would interact with Emacs packages?


[...]


> - Does this mean that "planner-el" is an elisp implementation of
> "planner"?

Is there another possible  implementation of planner?

> - If so, are there cases where there is a "foo-el" package that relies
> on a "foo" (non-elisp) application. In other words, can a situation
> arise when I am using an application in emacs and it exhibits odd
> behavior  because a non-emacs  application needs to be installed? If
> so, is it always obvious?

Sometimes ... emacs-w3m depends on w3m, which needs the gc garbage
collector.  AUCTeX requires a TeX system.

> And is there a straightforward way to tell if some package is already
> part of the emacs distribution I am using (so that I do  not attempt
> to download/install it myself)?

Look in the version-specific directories and the site-lisp directory
for the elisp files.  Or use slocate: "slocate planner.el"

My suggestion is install from source, then your know exactly where
everything is going, but I understand that is a difference of opinion
with potentially religious implications.

Joel
-- 
Joel J. Adamson
Biostatistician
Pediatric Psychopharmacology Research Unit
Massachusetts General Hospital
Boston, MA  02114
(617) 643-1432
(303) 880-3109