Yet another magic symlinks implementation

[Andrey V. Elsukov]

>    It is interesting to note that DragonFly has had variant symlnks for 
>    a long time, but we haven't actually found a use for them yet.   

Yes, Matt. Some time ago i've ported Df's variant symlinks too :)
http://butcher.heavennet.ru/patches/kernel/varsym/

This task was declared on the ideas page:
http://www.freebsd.org/projects/ideas/#p-magicsymlinks

But i don't see an interest in this feature among commiters. :( 

>    Originally I envisioned using variant symlinks as part of a packaging
>    system to allow package environments to be built on the fly, thus
>    allowing multiple versions of libraries to coreside and not have the
>    'you have to upgrade everything to install one new thing' problem.
>    But that was before we adopted pkgsrc.  Pkgsrc doesn't use varsyms,
>    so...

Yes, i think varsyms can be usefull in build enviroments. Somebody spoke that
varsyms can be usable in a cluster or jailed enviroments. But i think, that it
is necessary to change a priority of levels. The system level must have a hight
priority, and unprivileged users can not override system variables. 

For a NetBSD's magiclinks i see only one scope - build enviroment. 

-- 
WBR, Andrey V. Elsukov