文件目录 (一).stat（2）

struct dirent *de=NULL;

emacs@ubuntu:/usr/include$ grep dirent dirent.h  | head -n 3
 *	POSIX Standard: 5.1.2 Directory Operations	<dirent.h>
/* This file defines `struct dirent'.
#include <bits/dirent.h>
emacs@ubuntu:/usr/include$ 

#ifndef _DIRENT_H
# error "Never use <bits/dirent.h> directly; include <dirent.h> instead."
#endif

struct dirent
  {
#ifndef __USE_FILE_OFFSET64
    __ino_t d_ino; //索引节点号, inode number
    __off_t d_off; //在目录文件中的偏移,offset to this dirent  
#else
    __ino64_t d_ino; 
    __off64_t d_off;
#endif
    unsigned short int d_reclen;  
    unsigned char d_type; //文件类型, the type of d_name
    char d_name[256];           /* We must not include limits.h! */ //文件名，最长255字符 file name (null-terminated) 
  };

struct stat fs;

emacs@ubuntu:/usr/include$ grep stat sys/stat.h | grep include
#include <bits/stat.h>
emacs@ubuntu:/usr/include$ 

#ifndef _SYS_STAT_H
# error "Never include <bits/stat.h> directly; use <sys/stat.h> instead."
#endif


struct stat
  {
    __dev_t st_dev;		/* Device.  */  //文件使用的设备号
#if __WORDSIZE == 32
    unsigned short int __pad1;
#endif
#if __WORDSIZE == 64 || !defined __USE_FILE_OFFSET64
    __ino_t st_ino;		/* File serial number.	*/  //索引节点号
#else
    __ino_t __st_ino;			/* 32bit file serial number.	*/
#endif  //索引节点号
#else
#if __WORDSIZE == 32
    __mode_t st_mode;			/* File mode.  */  //文件访问权限  
    __nlink_t st_nlink;			/* Link count.  */  //文件的硬连接数
#else
    __nlink_t st_nlink;		/* Link count.  */  //文件的硬连接数
    __mode_t st_mode;		/* File mode.  */  //文件访问权限
#endif
    __uid_t st_uid;		/* User ID of the file's owner.	*/  //所有者用户识别号
    __gid_t st_gid;		/* Group ID of the file's group.*/  //组识别号
#if __WORDSIZE == 64
    int __pad0;
#endif
    __dev_t st_rdev;		/* Device number, if device.  */
#if __WORDSIZE == 32
    unsigned short int __pad2;
#endif
#if __WORDSIZE == 64 || !defined __USE_FILE_OFFSET64
    __off_t st_size;			/* Size of file, in bytes.  */  //以字节为单位的文件容量   
#else
    __off64_t st_size;			/* Size of file, in bytes.  */  //以字节为单位的文件容量   
#endif
    __blksize_t st_blksize;	/* Optimal block size for I/O.  */
#if __WORDSIZE == 64 || !defined __USE_FILE_OFFSET64
    __blkcnt_t st_blocks;		/* Number 512-byte blocks allocated. */ //该文件所占的磁盘块   
#else
    __blkcnt64_t st_blocks;		/* Number 512-byte blocks allocated. */
#endif
#ifdef __USE_MISC
    /* Nanosecond resolution timestamps are stored in a format
       equivalent to 'struct timespec'.  This is the type used
       whenever possible but the Unix namespace rules do not allow the
       identifier 'timespec' to appear in the <sys/stat.h> header.
       Therefore we have to handle the use of this header in strictly
       standard-compliant sources special.  */
    struct timespec st_atim;		/* Time of last access.  */  //最后一次访问该文件的时间
    struct timespec st_mtim;		/* Time of last modification.  */  //最后一次修改该文件的时间 
    struct timespec st_ctim;		/* Time of last status change.  */   //最后一次改变该文件状态的时间  
# define st_atime st_atim.tv_sec	/* Backward compatibility.  */
# define st_mtime st_mtim.tv_sec
# define st_ctime st_ctim.tv_sec
#else
    __time_t st_atime;			/* Time of last access.  */
    unsigned long int st_atimensec;	/* Nscecs of last access.  */
    __time_t st_mtime;			/* Time of last modification.  */
    unsigned long int st_mtimensec;	/* Nsecs of last modification.  */
    __time_t st_ctime;			/* Time of last status change.  */
    unsigned long int st_ctimensec;	/* Nsecs of last status change.  */
#endif
#if __WORDSIZE == 64
    long int __unused[3];
#else
# ifndef __USE_FILE_OFFSET64
    unsigned long int __unused4;
    unsigned long int __unused5;
# else
    __ino64_t st_ino;			/* File serial number.	*/
# endif
#endif
  };

#ifndef
#else
#endif