10 利用RTT的文件系统创建的CSV文件，在电脑端显示该文件的修改日期不对呢？

发布于 2022-05-25 16:10:15 浏览：1088 订阅该版

出出啊 2022-05-25

恃人不如自恃，人之为己者不如己之自为也

他们叫我小弟 2022-05-25

这家伙很懒，什么也没写！

ccxzjz 2022-05-25

写啥好呢

他们叫我小弟 2022-05-25

这家伙很懒，什么也没写！

出出啊 2022-05-25

恃人不如自恃，人之为己者不如己之自为也

他们叫我小弟 2022-05-26

这家伙很懒，什么也没写！

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3 个回答

他们叫我小弟 2022-05-25

这家伙很懒，什么也没写！

出出啊 2022-05-25

恃人不如自恃，人之为己者不如己之自为也

他们叫我小弟 2022-05-25

这家伙很懒，什么也没写！

```c
DWORD get_fattime(void)
{
    DWORD fat_time = 0;

#ifdef RT_USING_LIBC
    time_t now;
    struct tm *p_tm;
    struct tm tm_now;
	
    /* get current time */
    now = time(RT_NULL);
	rt_kprintf("now=%d",now);
    /* lock scheduler. */
    rt_enter_critical();
    /* converts calendar time time into local time. */
    p_tm = localtime(&now);
    /* copy the statically located variable */
    memcpy(&tm_now, p_tm, sizeof(struct tm));
    /* unlock scheduler. */
    rt_exit_critical();

fat_time = (DWORD)(tm_now.tm_year - 80) << 25 |
               (DWORD)(tm_now.tm_mon + 1)   << 21 |
               (DWORD)tm_now.tm_mday        << 16 |
               (DWORD)tm_now.tm_hour        << 11 |
               (DWORD)tm_now.tm_min         <<  5 |
               (DWORD)tm_now.tm_sec / 2 ;
		 
#endif /* RT_USING_LIBC  */

return fat_time;
}
```
get_fattime函数里面这个 now = time(RT_NULL)一直返回为0，
```c
extern _ARMABI time_t time(time_t * /*timer*/);
   /*
    * determines the current calendar time. The encoding of the value is
    * unspecified.
    * Returns: the implementations best approximation to the current calendar
    *          time. The value (time_t)-1 is returned if the calendar time is
    *          not available. If timer is not a null pointer, the return value
    *          is also assigned to the object it points to.
    */

```

time()函数定义在上面。不懂为什么这个可以get到时间当前值。