Re: [Synaptic-devel] Distribution selection

[Panu Matilainen]

On Tue, 2003-09-30 at 19:48, Michael Vogt wrote:
> On Tue, Sep 30, 2003 at 10:42:52AM +0300, Panu Matilainen wrote:
> > Quoting Sebastian heinlein <address@hidden>:
> [..]
> > > I was wrong on this. I haven't considered that this is actually apt
> > > pining.
> > 
> > Exactly. We should pay some careful attention - here's a chance to get an
> > understandable GUI presesntation/configuration of apt pinning which by 
> > fiddling
> > with apt preferences file and looking at apt-cache policy output (did it
> > understand what I did) is anything but nice.
> 
> Yes, I think so as well. There are some problems inside libapt that
> makes this a bit clumsy sometimes (libapt is not really designed for
> interactive use). We have a function in the policy engine of apt to
> create a pin, but not to remove it (which is importend if we want to
> chage the default release without rereading the whole cache). I'll ask
> on the debian-deity ML and Gustaco and see if we can get something
> like this. 
> 
> I know that the "release" scheme is more flexible than just having
> "stable/testing/unstable" :) My problem was that I wanted to see if it
> works and I have no idea right now how I can make libapt to tell me
> what releases are available (and what origions, that might be nice as
> well). Do you have any idea Panu? Or maybe Gustavo? 

Hmm, surprisingly straightforward actually :) The following code snippet
(tested in apt-cache policy routine) prints out the known components
along with their associated releases (archives) and origins:

for (pkgCache::PkgFileIterator F = Cache.FileBegin(); F.end() == false;
F++)
{
   pkgIndexFile *Indx;
   SrcList->FindIndex(F,Indx);
   _system->FindIndex(F,Indx);
                                                                                
   if (! F.RelStr().empty())
      printf("Archive: %s, Origin: %s, Component: %s\n", F.Archive(),
F.Origin(), F.Component());
}

In my config (using www.fedora.us repository) this looks like:
Archive: stable, Origin: Fedora, Component: stable
Archive: stable, Origin: Red Hat, Component: updates
Archive: stable, Origin: Red Hat, Component: os
Archive: unstable, Origin: Fedora, Component: unstable
Archive: testing, Origin: Fedora, Component: testing
Archive: stable, Origin: Fedora, Component: stable
Archive: unstable, Origin: Fedora, Component: unstable
Archive: testing, Origin: Fedora, Component: testing
Archive: stable, Origin: Fedora, Component: stable
Archive: unstable, Origin: Fedora, Component: unstable
Archive: testing, Origin: Fedora, Component: testing
Archive: stable, Origin: Fedora, Component: stable
Archive: stable, Origin: Red Hat, Component: updates
Archive: stable, Origin: Red Hat, Component: os

        - Panu -