linux下获得块设备大小

运行结果如下

jackie@Ubuntu:~/work/0602$ sudo ./a.out /dev/sda
/dev/sda
3907029168,2000398934016

//BLKGETSIZE64 获取空间大小 (bytes)

//BLKGETSIZE  获取块数量 * 512 = 空间大小 (在vmware esxi环境下这个不能用,还不知道原因)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <linux/fs.h>
#include <sys/ioctl.h>

int main(int argc,char *argv[]){

int fd;
off_t  space,space64;
fd = open(argv[1], O_RDONLY);

printf("%s\n",argv[1]);
if(fd == -1) {  
    printf("main: open device failed\n");  
        return -1;  
    }

if (ioctl(fd, BLKGETSIZE64, &space64)) {
                         perror("Get free space64 failed");
 close(fd);

return 1;
                 }

if (ioctl(fd, BLKGETSIZE, &space)) {
                          perror("Get free space failed");
 close(fd);
                         
return 1;
                   }

printf("%lu,%lu\n",space,space64);

close(fd);
}