stat 函数

 查询man 2 stat

SYNOPSIS

　　#include <sys/types.h>
　　#include <sys/stat.h>
　　#include <unistd.h>

　　int stat(const char *path, struct stat *buf);  

　　　//stat() stats the file pointed to by path and fills in buf.

　　int fstat(int fd, struct stat *buf);

　　　//fd是文件描述符

　　int lstat(const char *path, struct stat *buf);

　　//当文件是一个符号链接时，lstat返回的是该符号链接本身的信息

 

 

DESCRIPTION

 1 struct stat {
 2 dev_t st_dev; /* ID of device containing file 文件的设备编号*/
 3 ino_t st_ino; /* inode number 引索节点*/
 4 mode_t st_mode; /* protection 文件的类型和存取的权限*/
 5 nlink_t st_nlink; /* number of hard links 硬连接数*/
 6 uid_t st_uid; /* user ID of owner 用户ID*/
 7 gid_t st_gid; /* group ID of owner 用户组ID*/
 8 dev_t st_rdev; /* device ID (if special file) . The st_rdev field describes the device that this file (inode) represents.
　　　　　　　　　　　　如果这个是设备文件，那么它将描述的是在本设备文件（节点）的设备编号　*/
 9 off_t st_size; /* total size, in bytes 文件大小*/
10 blksize_t st_blksize; /* blocksize for file system I/O 块大小*/
11 blkcnt_t st_blocks; /* number of 512B blocks allocated 块数*/
12 time_t st_atime; /* time of last access 最后访问时间*/
13 time_t st_mtime; /* time of last modification 最后修改时间*/
14 time_t st_ctime; /* time of last status change . changed by writing or by setting inode information
　　　　　　　　　　　　　　最后一次被写、属性修改的时间*/
15 };

宏定义：

the st_mode field:


　　S_ISREG(m) is it a regular file?    是否为普通文件

　　S_ISDIR(m) directory?  是否为目录

　　S_ISCHR(m) character device?  是否为字符设备

　　S_ISBLK(m) block device?  是否为块设备

　　S_ISFIFO(m) FIFO (named pipe)?  是否为管道

　　S_ISLNK(m) symbolic link? (Not in POSIX.1-1996.) 是否为软链接

　　S_ISSOCK(m) socket? (Not in POSIX.1-1996.) 是否为套接字

 1            S_IFMT     0170000   bit mask for the file type bit fields
 2            S_IFSOCK   0140000   socket
 3            S_IFLNK    0120000   symbolic link
 4            S_IFREG    0100000   regular file
 5            S_IFBLK    0060000   block device
 6            S_IFDIR    0040000   directory
 7            S_IFCHR    0020000   character device
 8            S_IFIFO    0010000   FIFO
 9            S_ISUID    0004000   set UID bit
10            S_ISGID    0002000   set-group-ID bit (see below)
11            S_ISVTX    0001000   sticky bit (see below)
12            S_IRWXU    00700     mask for file owner permissions
13            S_IRUSR    00400     owner has read permission
14            S_IWUSR    00200     owner has write permission
15            S_IXUSR    00100     owner has execute permission
16            S_IRWXG    00070     mask for group permissions
17            S_IRGRP    00040     group has read permission
18            S_IWGRP    00020     group has write permission
19            S_IXGRP    00010     group has execute permission
20            S_IRWXO    00007     mask for permissions for others (not in group)
21            S_IROTH    00004     others have read permission
22            S_IWOTH    00002     others have write permission
23            S_IXOTH    00001     others have execute permission
defined st_mode

 

　　下面是用ｓｔａｔ函数写了一个　ｌｌ　（ｓｈｅｌｌ）

 

  1 #include<stdio.h>
  2 #include<sys/types.h>
  3 #include<sys/stat.h>
  4 #include<unistd.h>
  5 #include<string.h>
  6 #include<pwd.h>
  7 #include<grp.h>
  8 #include<time.h>
  9 #include<stdlib.h>
 10 #include<dirent.h>
 11 
 12 #define BUF_SIZE 11　　／／宏定义大小和错误值
 13 #define GET_OK 0
 14 #define GET_ERR -1
 15 
 16 
 17 int GetFileType(char *buf,mode_t tMode);　　　／／文件类型　
 18 int GetFilePermission(char *buf,mode_t tMode);　　／／文件权限
 19 
 20 
 21 int main()
 22 {
 23     //open dir
 24     DIR *dir=opendir(".");
 25     if(NULL == dir)
 26     {
 27         return -1;
 28     }
 29     //read dir
 30     struct dirent *pItem = NULL;　　　　／／初始化
 31     struct stat stInfo;
 32     char buf[BUF_SIZE] = {0};
 33     struct passwd *pPwd = NULL;
 34     struct group  *pGroup = NULL;
 35 
 36     while(NULL !=(pItem=readdir(dir)))
 37     {
 38         memset(&stInfo,0,sizeof(struct stat));
 39         memset(buf,0,BUF_SIZE);
 40         if(0 != stat(pItem->d_name,&stInfo))　　　　／／获取ｓｔａｔ结构体
 41         {
 42             continue;
 43         }
 44         // mode
 45         if(GET_OK != GetFileType(buf,stInfo.st_mode))
 46         {
 47             continue;
 48         }
 49 
 50         if(GET_OK != GetFilePermission(buf,stInfo.st_mode))
 51         {
 52             continue;
 53         }
 54 
 55         if(NULL == (pPwd = getpwuid(stInfo.st_uid)))
 56         {
 57             continue;
 58         }
 59         if(NULL == (pGroup = getgrgid(stInfo.st_gid)))
 60         {
 61             continue;
 62         }
 63         printf("%s %d %s %s %ld %s %s\r\n",buf,stInfo.st_nlink,pPwd->pw_name,pGroup->gr_name,stInfo.st_size,ctime(&stInfo.st_atime),pItem->d_name);
 64     }
 65     return 0;
 66 }
 67 
 68 int GetFileType(char *buf,mode_t tMode)
 69 {
 70     if(NULL == buf)
 71     {
 72         return GET_ERR;
 73     }
 74     buf[0]='-';
 75     if(S_ISREG(tMode)) buf[0]='-';
 76     if(S_ISDIR(tMode)) buf[0]='d';
 77     return GET_OK;
 78 }
 79 
 80 
 81 
 82 int GetFilePermission(char *buf,mode_t tMode)
 83 {
 84     if(NULL == buf)
 85     {
 86         return GET_ERR;
 87     }
 88 
 89     memset(buf+1,'-',BUF_SIZE-2);　　　　／／前一位已经被编写过了，移动
 90     if(tMode & S_IRUSR) buf[1]='r';　　　　　／／测试权限，最上面有宏定义可以看出，可以点＋号打开
 91     if(tMode & S_IWUSR) buf[2]='w';
 92     if(tMode & S_IXUSR) buf[3]='x';
 93 
 94     if(tMode & S_IRGRP) buf[4]='r';
 95     if(tMode & S_IWGRP) buf[5]='w';
 96     if(tMode & S_IXGRP) buf[6]='x';
 97 
 98     if(tMode & S_IROTH) buf[7]='r';
 99     if(tMode & S_IWOTH) buf[8]='w';
100     if(tMode & S_IXOTH) buf[9]='x';
101 
102     return GET_OK;
103 }

 

posted @ 2017-03-23 17:06  AAAron  阅读(546)  评论(0)  编辑  收藏  举报