ios 如何获取手机可用空间和总的存储空间的大小

#include 
#include 

- (void)getDivceSize{
    //可用大小
    struct statfs buf;
    long long freespace = -1;
    if(statfs("/var", &buf) >= 0){
        freespace = (long long)(buf.f_bsize * buf.f_bfree);
    }
    //总大小
    struct statfs buf1;
    long long maxspace = 0;
    if (statfs("/", &buf1) >= 0) {
        maxspace = (long long)buf1.f_bsize * buf1.f_blocks;
    }
    if (statfs("/private/var", &buf1) >= 0) {
        maxspace += (long long)buf1.f_bsize * buf1.f_blocks;
    }
    NSString * sizeStr = [NSString stringWithFormat:@"可用空间%0.2fG / 总空间%0.2fG",(double)freespace/1024/1024/1024,(double)maxspace/1024/1024/1024];
    self.sizeLabel.text = sizeStr;
    
}