stat函数

#include <sys/types.h>

#include <sys/stat.h>

#include <unistd.h>

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

返回值：

RETURN VALUE：
       On success, zero is returned.  On error, -1 is returned, and errno  is  set  appropri‐ately.

详细的 man 2 stat 查看

All  of  these  system  calls  return  a  stat structure, which contains the following　fields:

           struct stat {
               dev_t     st_dev;     /* ID of device containing file */
               ino_t     st_ino;     /* inode number */
               mode_t    st_mode;    /* protection */
               nlink_t   st_nlink;   /* number of hard links */
               uid_t     st_uid;     /* user ID of owner */
               gid_t     st_gid;     /* group ID of owner */
               dev_t     st_rdev;    /* device ID (if special file) */
               off_t     st_size;    /* total size, in bytes */
               blksize_t st_blksize; /* blocksize for file system I/O */
               blkcnt_t  st_blocks;  /* number of 512B blocks allocated */
               time_t    st_atime;   /* time of last access */
               time_t    st_mtime;   /* time of last modification */
               time_t    st_ctime;   /* time of last status change */
           };

 The following POSIX macros are defined to check the file type using the st_mode field:

           S_ISREG(m)  is it a regular file?

           S_ISDIR(m)  directory?

           S_ISCHR(m)  character device?

           S_ISBLK(m)  block device?

           S_ISFIFO(m) FIFO (named pipe)?

           S_ISLNK(m)  symbolic link? (Not in POSIX.1-1996.)

           S_ISSOCK(m) socket? (Not in POSIX.1-1996.)<pre name="code" class="cpp">














#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>


int main(int argc, char *argv[])
{
    struct stat buf;
    int n;
    if (argc != 2) {
	fprintf(stderr, "Use:%s <pathname>\n", argv[0]);
	exit(1);
    }



    n = stat(argv[1], &buf);
    if (n == -1) {
	perror("stat error");
    }

    switch (buf.st_mode & S_IFMT) {
		case S_IFBLK:
					printf("block device\n");	//块设备     
					break;
	    case S_IFCHR:
					printf("character device\n");	//字符设备
					break;
	    case S_IFDIR:
					printf("directory\n");	//目录
					break;
	    case S_IFIFO:
					printf("FIFO/pipe\n");	//FIFO 管道
					break;
	    case S_IFLNK:
					printf("symlink\n");	//指的是软连接
					break;
	    case S_IFREG:
					printf("regular file\n");	//普通文件
					break;
	    case S_IFSOCK:
					printf("sock\n");	//嵌套字
					break;
	    default:
					printf("unknown\n");
					break;
    }

    printf("Inode number:%ld\n", (long) buf.st_ino);
    printf("ID dev:%ld\n", (long) buf.st_dev);	//
    printf("nlink:%ld\n", (long) buf.st_nlink);	//硬链接数
    printf("UID:%ld\n", (long) buf.st_uid);
    printf("GID:%ld\n", (long) buf.st_gid);
    printf("Rdev:%ld\n", (long) buf.st_rdev);
    printf("Total size(byte):%ld\n", (long) buf.st_size);
    printf("number of 512B block allocated:%ld\n", (long) buf.st_blocks);
    printf("atime:%s", ctime(&buf.st_atime));
    printf("mtime:%s", ctime(&buf.st_mtime));
    printf("ctime:%s", ctime(&buf.st_ctime));

    return 0;
}

#if 0
struct stat {
    dev_t st_dev;		/* ID of device containing file */   设备ｉｄ
    ino_t st_ino;		/* inode number */　
    mode_t st_mode;		/* protection */　权限,类型
    nlink_t st_nlink;		/* number of hard links */ 硬链接
    uid_t st_uid;		/* user ID of owner */　　
    gid_t st_gid;		/* group ID of owner */
    dev_t st_rdev;		/* device ID (if special file) */　从设备ｉｄ
    off_t st_size;		/* total size, in bytes */　
    blksize_t st_blksize;	/* blocksize for file system I/O */ 块大小　
    blkcnt_t st_blocks;		/* number of 512B blocks allocated */　
    time_t st_atime;		/* time of last access */　最后访问存储时间
    time_t st_mtime;		/* time of last modification */　最后内容修改时间
    time_t st_ctime;		/* time of last status change */　最后权限修改时间
}
#endif

/*
akaedu@akaedu-G41MT-D3:~/lin/20140822_文件系统_stat$ ./1 file
regular file
Inode number:8782005
ID dev:2055
nlink:2
UID:1000
GID:1000
Rdev:0
Total size(byte):19
number of 512B block allocated:8
atime:Fri Aug 22 20:34:27 2014
mtime:Fri Aug 22 20:34:18 2014
ctime:Fri Aug 22 20:34:18 2014
akaedu@akaedu-G41MT-D3:~/lin/20140822_文件系统_stat$ ./1 a
directory
Inode number:8782007
ID dev:2055
nlink:2
UID:1000
GID:1000
Rdev:0
Total size(byte):4096
number of 512B block allocated:8
atime:Fri Aug 22 20:00:10 2014
mtime:Fri Aug 22 20:00:10 2014
ctime:Fri Aug 22 20:00:10 2014
akaedu@akaedu-G41MT-D3:~/lin/20140822_文件系统_stat$ 
*/