typedef int mapid_t;
#define MAP_FAILED ((mapid_t) -1)
+#define READDIR_MAX_LEN 14
+
void halt (void) NO_RETURN;
void exit (int status) NO_RETURN;
pid_t exec (const char *file);
void munmap (mapid_t);
bool chdir (const char *dir);
bool mkdir (const char *dir);
-void lsdir (void);
+bool readdir (int fd, char name[READDIR_MAX_LEN + 1]);
+bool isdir (int fd);
#endif /* lib/user/syscall.h */