Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
Description
VSgetclass retrieves the class name of the vdata identified by the parameter vdata_id and places it in the buffer vdata_class.
Space for the buffer vdata_class must be allocated by the calling program before VSgetclass is called. The maximum length of the class name is defined by the macro VSNAMELENMAX (or 64).