使用 fscanf() 的分段错误

Question

我正在尝试读取一个非常简单的数据文件，如下所示：

1597 1 0 3 1 

使用以下代码：

void boot(){
FILE *f = fopen("shutdown.txt", "r");
    uint8_t timestamp = 0;
    uint8_t power_down_type = 0;
    uint8_t power_down_cause = 0;
    uint8_t boot_number = 0;
    uint8_t antenna_deployed = 0;
    uint8_t images_captured = 0;

    fscanf(f, "%u %d %d %d %d %d", &timestamp, &power_down_type, &power_down_cause, &boot_number, &antenna_deployed, &images_captured);

    printf("timestamp: %u\n", timestamp);
    printf("power_down_type: %d\n", power_down_type);
    printf("power_down_cause: %d\n", power_down_cause);
    printf("boot_number: %d\n", boot_number);
    printf("antenna_deployed: %d\n", antenna_deployed);
    printf("images_captured: %d\n", images_captured);
}

但是当我运行代码时，我得到了一个 SEGV 错误。

Answer 1

%d 读取 int 和 %u 读取 unsigned int，两者都大于 uint8_t。通过写入超过变量的大小会发生未定义的行为。 %hhu 应该用于uint8_t。