Availability:C-language interface function
int PL_get_pointer(term_t 
+t, void **ptr)In the current system, pointers are represented by Prolog integers, but 
need some manipulation to make sure they do not get truncated due to the 
limited Prolog integer range. PL_put_pointer() 
and PL_get_pointer() 
guarantee pointers in the range of malloc() are handled without 
truncating.