``variant'' links

[steve at umiacs.umd.edu]

The Sprite operating system does this, but (from what little I know) just
for $MACHINE, not for any environment variable.  If I were implementing
this, I'd just hardcode something into the Sprite equivalent of namei to
look for $MACHINE, then turn it into an architecture name.  It looks like
this is what Sprite does, in fact.

One thing that worries me about variant links is that you have to be a
little bit careful when implementing this in order not to toss security
out the window.  If you can get something running as root to exec
something, and diddle the path to that something so that it runs your
program instead, you've now got a root shell.  There are probably ways to
make this secure, but I haven't given the issue a lot of thought.

Spoken: Steve Miller    Domain: steve at umiacs.umd.edu    UUCP: uunet!mimsy!steve
Phone: +1-301-454-1808  USPS: UMIACS, Univ. of Maryland, College Park, MD 20742