User installation of plugins and applications

[Mike Hearn]

On Mon, 2003-07-28 at 21:23, George Staikos wrote:
> It would be nice if users could install (in a distro/OS neutral 
> way) to their home directory somehow.  This might even lead to the ability to 
> share some of these types of things in the future.

We had a guy who added this ability to autopackage a while ago, it works
OK. Basically:

* the app must be relocatable (ie, it should be able to figure out its
prefix for data files at runtime). We have a little library that helps 
apps do that, but it needs a lot of work.
* You need some way to package it that can be installed to the user
directory.

For the second point, a plain old binary tarball works OK. We've taken
to installing to ~/.local by default as that seemed to be the preferred
directory here for such things. You can make RPMs relocatable too,
though I've been told that this ability is broken in some versions (like
the one in RH8? not sure)

> For instance: I am developing a scientific application right now and root 
> access is just not always possible for the users.  The plugins are actually 
> just plain C objects with an XML interface description.  Other applications 
> use these plugins as well, and it would be nice if they all could look in the 
> same place for their plugins.  With a defined standard, we could enable this 
> sort of behaviour.

I'm not sure a generic plugins location makes much sense. It becomes a
lot easier to write loaders if you can just point at a well known
directory and hoover up all the DSOs in there, rather than having to
figure out whether they are plugins for you or not.

Probably it just makes sense to come to an informal agreement between
the vendors of this type of application on where to put plugins, like
how there's informal agreement that /usr/lib/win32 is where proprietary
windows video plugin DLLs are put for mplayer/xine.

thanks -mike

-- 
Mike Hearn <m.hearn at signal.qinetiq.com>
QinetiQ - Malvern Technology Center