POSIX

struct dirent {
  ino_t          d_ino;       /* Inode编号 */
  off_t          d_off;       /* 不是偏移量，详见下文 */
  unsigned short d_reclen;    /* 此记录的长度 */
  unsigned char  d_type;      /* 文件类型，不是所有文件系统都支持 */
  char           d_name[256]; /* 以空字符结尾的文件名 */
};


#define DT_UNKNOWN 0 // Unknown file type
#define DT_FIFO    1 // FIFO (named pipe)
#define DT_CHR     2 // Character device - 字符设备
#define DT_DIR     4 // Directory - 目录
#define DT_BLK     6 // Block device - 块设备
#define DT_REG     8 // Regular file - 文件
#define DT_LNK    10 // Symbolic link - 符号链接
#define DT_SOCK   12 // Socket - 套接字
#define DT_WHT    14 //

int            alphasort(const struct dirent **, const struct dirent **);
int            closedir(DIR *);
int            dirfd(DIR *);
DIR           *fdopendir(int);
DIR           *opendir(const char *);
ssize_t        posix_getdents(int, void *, size_t, int);
struct dirent *readdir(DIR *);
int            readdir_r(DIR *restrict, struct dirent *restrict, struct dirent **restrict);
void           rewinddir(DIR *);
int            scandir(const char *, struct dirent ***, int (*)(const struct dirent *), int (*)(const struct dirent **, const struct dirent **));
void           seekdir(DIR *, long);
long           telldir(DIR *);