#include <db.h> int db_env_set_func_free(void (*func_free)(void *ptr));
Replace Berkeley DB calls to the ANSI C X3.159-1989 (ANSI C) standard free function with func_free, which must conform to the standard interface specification.
         The db_env_set_func_free() function configures all operations performed by
         a process and all of its threads of control, not operations confined
         to a single database environment.
    
         Although the db_env_set_func_free() function may be called at any time
         during the life of the application, it should normally be called
         before making calls to the db_env_create or
         db_create methods.
    
         The db_env_set_func_free() 
                  function returns a non-zero error value on failure and 0 on success.