#include?“stdio.h“
#include?“string.h“
#include?“conio.h“
#include?“stdlib.h“
#define?MAXNAME?25??/*the?largest?length?of?mfdnameufdnamefilename*/
#define?MAXCHILD?50?/*the?largest?child*/
#define?MAX?（MAXCHILD*MAXCHILD）?/*the?size?of?fpaddrno*/

typedef?struct??/*the?structure?of?OSFILE*/
??{int??fpaddr;????????????????/*file?physical?address*/
???int??flength;???????????????/*file?length*/
???int??fmode;???/*file?mode:0-Read?Only;1-Write?Only;2-Read?and?Write（default）;*/
???char?fname[MAXNAME];????????/*file?name*/
??}?OSFILE;

typedef?struct?????/*the?structure?of?OSUFD*/
??{char?ufdname[MAXNAME];???/*ufd?name*/
???OSFILE?ufdfile[MAXCHILD];???/*ufd?own?file*/
??}OSUFD;

typedef?struct??/*the?structure?of?OSUFD‘LOGIN*/
??{char?ufdname[MAXNAME];???????/*ufd?name*/