[gentoo-dev] Handling compatible multi tools

[Diego 'Flameeyes' Pettenò]

Hi everybody,
Please don't start flaming me for this proposal, it's a discussion.

Now, we have in tree app-arch/bsdtar and app-arch/tar (gnu tar) that are 
syntax compatible and can actually work fine on Gentoo/Linux or 
Gentoo/FreeBSD or anything Gentoo/*..

Now they are probably the only two of a series of tools that might be choosen 
from a list.

I already tried preparing a list, but right now, they are probably limited to 
tar and mpg123/mpg321 ... sort of.

What I was thinking of is to standardize a way they can be handled. A part an 
eselect module, what I was thinking of was a way to have (in this 
case) /bin/tar remain what it is if it's a symlink.

Basically, I thought of this:

* don't install the symlink in src_install
* in pkg_postinst, look at ${ROOT}/bin/tar.. if it does exists, and it points 
on something existing, don't touch it, otherwise, make it a link to the 
current tar
* in pkg_postrm, if ${ROOT}/bin/tar points to something non existant, remove 
it

at this point, gnu tar and bsdtar might share a virtual, and one can choose 
the tar to use (obviously, the default remains on the os default tar, so 
bsdtar for freebsd, and gnu tar for everything else).

It's probably incomplete, so I like proposals about this...
-- 
Diego "Flameeyes" Pettenò - http://dev.gentoo.org/~flameeyes/
Gentoo/ALT lead, Gentoo/FreeBSD, Video, AMD64, Sound, PAM, KDE