Re: odt file instant open

["Andreas Röhler" <andreas.roehler@easy-emacs.de>]

Am 28.07.2010 15:10, schrieb Kevin Rodgers:
> Andreas Röhler wrote:
>> Am 27.07.2010 18:58, schrieb Eli Zaretskii:
>>>> Date: Tue, 27 Jul 2010 09:30:32 +0200
>>>> From: Andreas Röhler<andreas.roehler@easy-emacs.de>
>>>>
>>>> Am 26.07.2010 18:29, schrieb Olwe Melwasul:
>>>>> I'm trying to grok the open document format, so I took the first wild
>>>>> and crazy step of simply trying to open it in Emacs (23.2.1) -- and it
>>>>> opened up to a "Zip-Archive Narrow" view of all the files contained
>>>>> therein Poking around on the Internet, I found that Emacs
>>>>> automatically unpacks a .odt file, which is nothing more than a zip
>>>>> file. My question is this: How is Emacs doing this?
>>>>
>>>> by calling a shell-command resp. to the ending found.
>>>
>>> No. For most archive types, arc-mode.el (and tar-mode.el) can list
>>> the contents directly, just by reading the archive file itself.
>>> Extracting the individual files in the archive sometimes needs to run
>>> an external program.
>>
>> Hi,
>>
>> think you mistook the question.
>> As the OP wrote, he just opened the file without any precaution. The
>> surprise was: it worked.
>>
>> Ignoring so for how opening was done in detail --via find-file or from
>> dired probably--
>
> I think you misread the question, that is exactly what the OP asked about:
>
> How is Emacs doing this? What code is
> running (what .el is invoked) to make this happen?
>
>> arc-mode seems not involved, but auto-compression-mode from
>> jka-cmpr-hook.el etc.
>
> This entry from auto-mode-alist suggests otherwise:
>
> ("\\.\\(sx[dmicw]\\|od[fgpst]\\|oxt\\)\\'" . archive-mode)
>

You are right here, Eli too. So the mistake is mine in this point.
.odt is handled differently from other archives as


  ("\\.g?z\\(~\\|\\.~[0-9]+~\\)?\\'" nil jka-compr)
  ("\\.bz2\\(~\\|\\.~[0-9]+~\\)?\\'" nil jka-compr)
  ("\\.Z\\(~\\|\\.~[0-9]+~\\)?\\'" nil jka-compr)

where I poked around some weeks ago...

Thanks

Andreas



>> BTW arc-mode too recurs to shell-commands AFAIS,
>> (apply 'call-process
>> in archive-*-extract for example
>
> Good point, which Eli made above as well. Here's what arc-mode.el says:
>
> ;; This code does not decode any files internally, although it does
> ;; understand the directory level of the archives.
>