获取sd卡总容量，可用空间，最轻的写法
#define THRESHOLD_BYTES (60LL * 1024 * 1024) // 60MB int get_sdcard_space(int *free_bytes_mb, int *total_bytes_mb) { struct statfs fs; if (statfs("/mnt/sdcard", &fs) != 0) { perror("statfs failed"); return -1; } // 计算空间（以字节为单位） long long free_bytes = (long long)fs.f_bsize * (long long)fs.f_bavail; long long total_bytes = (long long)fs.f_bsize * (long long)fs.f_blocks; // 转换为MB并输出 int free_mb = free_bytes / 1024 / 1024; int total_mb = total_bytes / 1024 / 1024; // 通过指针返回结果 if (free_bytes_mb) *free_bytes_mb = free_mb; if (total_bytes_mb) *total_bytes_mb = total_mb; printf("SD total size = %lld bytes (%d MB)\n", total_bytes, total_mb); printf("SD free space = %lld bytes (%d MB)\n", free_bytes, free_mb); // 检查是否超过阈值 if (free_bytes > THRESHOLD_BYTES) { return 1; // 空间充足 } else { return -1; // 空间不足 } } // 调用示例 int total, free; int ret; // 获取 sd卡可用空间 ret = get_sdcard_space(&free, &total); if(ret == 1) { resp.total = total; resp.free = free; } else { resp.total = -2; // -2代表空间不足，只能回放录像 resp.free = free; }
