SPUG: Understanding RUID EUID and modules (fwd)

[Jacinta Richardson]

You might have some luck understanding this if you have a look at what Paul 
Fenwick did in Proc::UID (which I'll have to bump him on to get it "production 
ready").  Although he might use $< and $>, I can't remember.  There's a 
Perlmonks thread at  http://perlmonks.org/?node_id=361909
too.

I remember him finding a bug in handling of $< and $>, in that they _cache_ the 
*id results.  This means that if you call an external program, or use a C 
routine which makes changes to them, $< and $> might be wrong.

	J