On Sat, Apr 19, 2003 at 02:07:04PM +0100, Matt Ryan wrote: > Personally I use the ask-about-overwrite question in debconf because the > last time this thread came up the only sensible solution was put forward > in the attached email. Now, I'm all for a better solution when it is > determined what that is, *but* I'm not for a witch hunt based on what was > seen to be previous best practice.
There was a more recent discussion about the same idea. A summary of the goals: - Don't try to parse every program's configuration file format - Notice that a non-conffile, autogenerated configuration file has been modified by the user, and don't lose their changes - Provide 3-way merge functionality to incorporate changes without losing modifications in the common case (I hear this is coming for conffiles as well) - Use debconf for prompting - Have all packages do this using a standard toolset, so that all prompting is consistent and well-translated, and certain defaults can be set globally (see the threads below for more discussion about this) I have a clear idea of how I would implement this (and even some code), and I think that these are all achievable. The one thing which would be sacrificed is preconfiguration. Since autogenerated configuration files, unlike conffiles, require non-essential tools in order to build them, this work generally needs to be done in the postinst. This means that we can't know what the "new" configuration file looks like until the package is being configured. And there's no sense prompting the user ahead of time when they can't see what the changes look like (Do you want to overwrite your modifications with some random garbage I can't show you now? [Yes/No]). Consider xserver-xfree86, whose current debconf setup can use autodetection data from mdetect and read-edid, but this cannot work unless these packages are installed when xserver-xfree86's .config script runs. There is no dependency relationship which can provide this guarantee (and it doesn't sound like a very good idea to have one), so I don't see much of a way around this. However, I think that with suitable defaults and priority settings, the above goals might be worth a sacrifice. Of course, if someone can think up a way to make this work _correctly_ (in terms of user experience) with preconfiguration, that would be fabulous. Prompting about these configuration files in postinst would be no better or worse than the current conffile mechanism, though as Branden pointed out in the previous discussion, the conffile prompting could, in theory, be done at preconfiguration time, since the conffile itself is available in the deb. Generated configuration files, however, are not. What do folk think about this tradeoff? Or is there a way around it? References: http://lists.debian.org/debian-devel/2002/debian-devel-200210/msg01572.html http://lists.debian.org/debian-x/2002/debian-x-200210/msg00417.html -- - mdz
