How do I determine the length of resource forks from MCL?

[dmg@goldilocks.LCS.MIT.EDU (David Goodine)]

I'm trying to find a means of determining the resource fork size of
files in the Mac filesystem.  I've spent some time looking through
Inside Mac VI, and can't find out where the info is stored.  I expect
that it is somehow accessible through a trap or function call but FInfo,
DXInfo, et al, fall short.

Any suggestions would be greatly appreciated, as I'm on a very tight
deadline.  Please respond to me, as I'm not currently on the INFO-MCL
mailing list.

David Goodine
MIT Spoken Language System Group