Linux 使用statvfs读取文件系统信息

使用statvfs读取文件系统信息

///文件操作偏移地址启用64位形式

#define _FILE_OFFSET_BITS 64

#include <stdio.h>

#include <sys/statvfs.h>

typedef enum {

TOTAL_SIZE,///文件系统的大小

FREE_SIZE, ///自由空间

USED_SIZE, ///已用空间

AVAIL_SIZE ///用户实际可以使用的空间

}VFsize;

//把数字大小转换成字符形式

char *

byte_size_to_string(fsblkcnt_t size)

{

const double k = 1024;

const double m = k*1024;

const double g = m*k;

static char size_str[128] = {0};

if(size>=g)

sprintf(size_str,"%0.2lf GB",size/g);

else if(size>=m)

sprintf(size_str,"%0.2lf MB",size/m);

else if(size>=k)

sprintf(size_str,"%0.2lf KB",size/k);

else

sprintf(size_str,"%0.0lf Byte",size>=0?size:0.0);

return size_str;

}

///文件系统的各种信息数据的大小

fsblkcnt_t

get_vfs_size(struct statvfs *buf,VFsize flag)

{

fsblkcnt_t block;

fsblkcnt_t bsize;

bsize = buf->f_bsize;

switch (flag){

case TOTAL_SIZE:

block = buf->f_blocks;

break;

case FREE_SIZE:

block = buf->f_bfree;

break;

case USED_SIZE:

block = buf->f_blocks - buf->f_bavail;

break;

case AVAIL_SIZE:

block = buf->f_bavail;

break;

default:

block = 0;

break;

}

return bsize * block;

}

int main(int argc, char **argv)

{

char *pathname;

struct statvfs buf;

fsblkcnt_t total_size;

fsblkcnt_t used_size;

fsblkcnt_t avail_size;

int error;

pathname = "/";

if(argc>1){

pathname = argv[1];

}

//把文件系统信息读入 struct statvfs buf 中

error = statvfs(pathname,&buf);

//错误检查

if(error <0){

fprintf(stderr,"statvfs():%m\n");

return error;

}

//输出结果，此结果与gparted一致，与df出入较大

printf("FileSystem of \'%s\':\n",pathname);

total_size = get_vfs_size(&buf,TOTAL_SIZE);

printf(" total:%s\n",byte_size_to_string(total_size));

used_size = get_vfs_size(&buf,USED_SIZE);

printf(" used :%s\n",byte_size_to_string(used_size));

avail_size = get_vfs_size(&buf,AVAIL_SIZE);

printf(" Avail:%s\n",byte_size_to_string(avail_size));

return 0;

}