Universal Extractor

[Simon McVittie]

On 11/02/15 18:08, Alexandre Detiste wrote:
> This is windows only stuff, I don't even know in which language it is;

An NSIS-like scripting language.

> but it is GPL-2 and we can use as a reference

Sorry, I already tried, and it isn't so useful - it's just a frontend.
The actual unpacking is done by a pile of random Windows executables;
for the ones that are open source, we mostly have the same thing in
Debian already.

For instance, the unpacker we'd need for the RTCW installer and the Jedi
Academy patch (if I remember correctly) is
<http://www.angelfire.com/ego/jmeister/hwun/index.html>, which is
source-available but non-DFSG, and appears to be written in a
DOS-specific dialect of Pascal, with comments in German. Not really the
droid we are looking for. (I tried compiling it in FreePascal just in
case it worked, but it didn't.)

If we're OK with running random Windows executables under Wine (which
I'd really rather not encourage for the sort of root-equivalent user who
can usefully run g-d-p), then we might as well just run the installers
under Wine instead - Windows installers often have a command-line option
to dump out the files they contain into a directory.

HWUN does point to one interesting bit of information, which is that
each installable file in a WISE installer is normally a raw deflate
stream at some offset in the installer binary. If we can work out the
offsets and lengths once (for instance by running the precompiled HWUN
executable in a sandbox, although it's really really slow for something
as big as RTCW), we could maybe hard-code those in the YAML, and teach
g-d-p to unpack them with zlib...

    S