visiting large zip file

visiting large zip file

[Kin Cho]

Hi,

Visiting a large zip file to list the contents of the zip file
doesn't work if the zip file size exceeds the emacs buffer size
limit.

Obviously this is not the way it should work since the zip file
content doesn't need to be read into the buffer.

Is there a fix for this?

-kin

Re: visiting large zip file

[Benjamin Riefenstahl]

Hi Kin,


Kin Cho <kin@neoscale.com> writes:
> Visiting a large zip file to list the contents of the zip file
> doesn't work if the zip file size exceeds the emacs buffer size
> limit.
> 
> Obviously this is not the way it should work since the zip file
> content doesn't need to be read into the buffer.

In my setup the variable auto-mode-alist says that ZIP files are
handled by archive-mode.  This is defined in arc-mode.el.  Right at
the top of that file is a table that indicates that viewing is an
*internal* operation for all archive file types.  So Emacs does
actually need to read the file to interpret it.

I haven't found a way to use external tools instead in arc-mode.el.


Sorry, benny

Re: visiting large zip file

[Eli Zaretskii]

> From: Kin Cho <kin@neoscale.com>
> Newsgroups: gnu.emacs.help
> Date: 31 Jan 2003 16:38:44 -0800
> 
> Visiting a large zip file to list the contents of the zip file
> doesn't work if the zip file size exceeds the emacs buffer size
> limit.
> 
> Obviously this is not the way it should work since the zip file
> content doesn't need to be read into the buffer.

Actually, the Emacs mode that supports operations on *.zip files
_does_ read the whole zip file into a buffer; hence the problem.

Re: visiting large zip file

[Stefan Monnier <foo@acm.com>]

>> Obviously this is not the way it should work since the zip file
>> content doesn't need to be read into the buffer.
> Actually, the Emacs mode that supports operations on *.zip files
> _does_ read the whole zip file into a buffer; hence the problem.

But I think Kin's point still holds: Emacs does not *need* to read
the file, since it uses external tools to extract/list/...
Contrary to tar-mode, for example.


        Stefan

Re: visiting large zip file

[Eli Zaretskii]

On 3 Feb 2003, Stefan Monnier <foo@acm.com> wrote:

> > Actually, the Emacs mode that supports operations on *.zip files
> > _does_ read the whole zip file into a buffer; hence the problem.
> 
> But I think Kin's point still holds: Emacs does not *need* to read
> the file, since it uses external tools to extract/list/...

I'm guessing that whoever wrote arc-mode tried to avoid external tools as 
much as they could, since some of the wide-spread tools are not free 
software, and the free ones might not be installed.  Also, IIRC arc-mode 
allows you to edit the file's attributes in ways that might be 
impossible with external tools.

Anyway, if someone wants to rewrite those parts of arc-mode to use 
external tools, or perhaps fall back on that if the file's size is too 
large for Emacs, I'm sure that would be a welcome addition.

> Contrary to tar-mode, for example.

tar-mode _could_ do the same (i.e. use the external `tar' program).

Re: visiting large zip file

[Bijan Soleymani]

"Stefan Monnier <foo@acm.com>" <monnier+gnu.emacs.help/news/@flint.cs.yale.edu> writes:

> >> Obviously this is not the way it should work since the zip file
> >> content doesn't need to be read into the buffer.
> > Actually, the Emacs mode that supports operations on *.zip files
> > _does_ read the whole zip file into a buffer; hence the problem.
> 
> But I think Kin's point still holds: Emacs does not *need* to read
> the file, since it uses external tools to extract/list/...
> Contrary to tar-mode, for example.
> 
> 
>         Stefan
Technically it doesn't. Emacs simply opens the file to determine the
contents by itself. If it didn't do this it would have to deal with
the different switches used by various "unzip" programs out there to
list the contents of an archive (not to mention having to reformat the
output of such a listing). Wouldn't be so hard but might cause
problems if people use nonstandard tools.

Bijan