函数名: fcloseall 
 功  能: 关闭打开流 
 用  法: #include <stdio.h> 
         int fcloseall(void); 
 程序例: 
#include <stdio.h>
int main(void) 
 { 
    int streams_closed; 
   /* open two streams */ 
    fopen("DUMMY.ONE", "w"); 
    fopen("DUMMY.TWO", "w"); 
   /* close the open streams */ 
    streams_closed = fcloseall(); 
   if (streams_closed == EOF) 
       /* issue an error message */ 
       perror("Error"); 
    else 
       /* print result of fcloseall() function */ 
       printf("%d streams were closed.\n", streams_closed); 
   return 0; 
 }