Help with C data types

[Ric Cowan <cowan@aerospace.aero.org>]

I'm trying to read data from a database written by a C program.  It
contains, among other data types, C strings, float, double, and extended
data.  It was written with FSOpen, SetFPos, fsWrite, etc. So the
routines in mac-file-io.lisp are perfect for reading the data values.

The problem I'm having is specifing the right data types for storage and
manipulation in memory.  I think I would like to be able to specify
fields of type :float and :double in defrecords and have a %get-cstr.

Any suggestions are welcome.  I'm currently using MCL 2.0b1.

Thanks
  Ric Cowan
  cowan@aero.org