Re: extracting a zip archive via elisp (with no external executables)

["Saulius Menkevičius" <saulius.menkevicius@gmail.com>]

Am 09.07.2017 um 22:45 schrieb Eli Zaretskii <eliz@gnu.org>:
> 
>> From: Saulius Menkevičius <saulius.menkevicius@gmail.com>
>> Date: Sun, 9 Jul 2017 22:26:45 +0300
>> Cc: Alan Third <alan@idiocy.org>, Emacs developers <emacs-devel@gnu.org>
>> 
>> I am one of the maintainers of the C# package for emacs https://github.com/OmniSharp/omnisharp-emacs
>> For the package to work properly it needs to run language server, which
>> should be downloaded from https://github.com/OmniSharp/omnisharp-roslyn/releases
>> 
>> I have added a new interactive command omnisharp-install-server which
>> downloads and installs the server to ~/.emacs.d/.cache/omnisharp/server/<version> directory.
>> Thus aleviating the need for the user to navigate to web page, download, extract
>> and the configure package to point to the location where the server has been extracted.
>> 
>> For UNIX systems things are easy, I just download tarball and extract it with (call-process „tar“ .. „xz“..)
>> 
>> But on Windows things get tough, apparently.
> 
> Not really.  This should get them going:
> 
>     (w32-shell-execute "open" "FILENAME.zip")
> or
>     (w32-shell-execute "explore" "FILENAME.zip")
> 
> (replace FILENAME.zip with the actual file name).  This will open the
> Windows Explorer showing the contents of the zip archive, and you
> should tell your users to click "File->Extract all" to extract the
> files into the directory of their choosing.
> 
>> Instructing the user to install 7-zip or something else manually kind of
>> invalidates the purpose of automatic installation.
> 
> Please never suggest to install 7z, it's not Free Software on Windows
> (and on Unix it's less capable to make it Free Software).  If someone
> needs 7z capabilities, the best Free Software alternative is bsdtar
> from the libarchive project.

My questions is still, is it possible to avoid involving user in this procedure?

Or do I need to roll out my own zip parser + extractor in elisp to do so :(
Which is probably slightly complicated thing to do.. Compared to what I
am trying to achieve.

-Saulius