Re: [Synaptic-devel] Hello and some questions

[Michael Vogt]

Hi,

On Thu, Jul 28, 2005 at 04:23:58PM +0200, Josué Alcalde González wrote:
> Hello. I am a newbie in this list. I have suscribed to ask for help.
> 
> I want to contrib to free software and I find no way to easy install 
> local debian packages in a gui.

Yes, that's a big missing feature. The biggest problem I had with
implementing this feature is that apt does not have a way to do
dependency resolution for local packages. I wonder how you solved this
problem? There is a patched apt around that can actually install local
packages but I guess you don't use it? 

> I decided to do a program with a look&feel similar to Synaptic, to see 
> the package properties, and then to try to do an installer for local 
> packages.
> 
> I have been studying Synaptic source code, and I have taken much of the 
> work. It is a c++ program and a libglade program, so I am using the 
> interfaces like RGWindow, RGGladeWindow, RGDialog... I also use other 
> goodies like the error mechanism or the section_trans.
> I supposed there is no problem since it is GPL.

That's sounds very nice! Is your sourcecode available somewhere? I'm
curious :)

> If you want to see an screenshot: 
> http://developer.berlios.de/dbimage.php?id=1882
> 
> I would want ask two questions:
> 
> 1) I would want to know if there is any documentation about synaptic 
> param options. I would like to know how non-interactive options works, 
> and what are the posibilities. I would also want if there is any option 
> to update only one repository.

I'm not sure what exactly you want to know. Synaptic can be run in
non-interactive mode to make it easy for other applications to call
certain services from apt. E.g.: 
# synaptic --update-at-startup --hide-main-window --non-interactive
will hide the main window, run "reload" and then exit (non-interactive
behaves as if the user has clicked "apply". It can be used with
"--upgrade" or "--dist-upgrade" (or --set-selections) as well.
Does that answer your question? Or did I misunderstand it :) ?

> 2) I have been trying to understand libapt-pkg to do one thing but I am 
> not able (I don't know if it is possible). I would like to know how to 
> extract a file in a deb file. The idea is to extract the changelog which 
> is present in most of debian packages which is in 
> package_name.deb>>data.tar.gz>>/usr/share/doc/package_name/changelog.Debian.gz>>changelog.Debian
> 
> Could it be made with the libapt-pkg library?

You will need the libapt-inst for this (part of apt, it contains of
libapt-pkg and libapt-inst). In apts sourcecode in
"cmdline/apt-extracttemplates.cc" is a DebFile class that does pretty
much what you want. You just need to customize it so that it extracts
changelogs (and not "config", "control", "templates" as it does now.
Thinking about it, it would be cool if you could make it generic
enough so that the current apt-extracttemplates could use your new
class and we could move that into libapt-inst directly.


Cheers,
 Michael

-- 
Linux is not The Answer. Yes is the answer. Linux is The Question. - Neo