Help in dealing with floating point exceptions in C on UNIX/VAX

[kgodfrey at prophet.bbn.com]

I'm new to C, and I'm trying to get some C code from an outside vendor to
run on a VAX running Berkeley 4.3 UNIX.  The problem I'm having is that
I can't figure out how to trap floating point exceptions.  I've tried
the infnan routine mentioned in the 4.3 manual, but I'm obviously doing
something wrong.  It seems to me there must be some reasonable way to
deal with this problem, but I've exhausted the expertise in my immediate
vicinity.  Can someone help me rescue myself from core dumps?

What I'd like to do is have the procedure propagate REALLY_BIG_NUMBER
when it gets an arithmetic overflow, instead of hitting infinity and
core dumping.

Thanks for any help/advice/leads.

Kathy Godfrey  
kgodfrey at prophet.bbn.com