函数名: farcoreleft 
 功  能: 返回远堆中未作用存储区大小 
 用  法: #include <alloc.h>
         long farcoreleft(void); 
 程序例: 
#include <stdio.h> 
 #include <alloc.h> 
int main(void) 
 { 
    printf("The difference between the\ 
     highest allocated block in the\ 
            far\n"); 
    printf("heap and the top of the far heap\ 
            is: %lu bytes\n", farcoreleft()); 
   return 0; 
 }