fatfs/documents/doc/fattime.html

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   9 <title>FatFs - get_fattime</title>
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  13
  14 <div class="para func">
  15 <h2>get_fattime</h2>
  16 <p>The get_fattime function is called to get the current time.</p>
  17 <pre>
  18 DWORD get_fattime (void);
  19 </pre>
  20 </div>
  21
  22
  23 <div class="para ret">
  24 <h4>Return Value</h4>
  25 <p>Currnet local time shall be returned as bit-fields packed into a <tt>DWORD</tt> value. The bit fields are as follows:</p>
  26 <dl class="ret">
  27 <dt>bit31:25</dt>
  28 <dd>Year origin from the 1980 (0..127, e.g. 37 for 2017)</dd>
  29 <dt>bit24:21</dt>
  30 <dd>Month (1..12)</dd>
  31 <dt>bit20:16</dt>
  32 <dd>Day of the month (1..31)</dd>
  33 <dt>bit15:11</dt>
  34 <dd>Hour (0..23)</dd>
  35 <dt>bit10:5</dt>
  36 <dd>Minute (0..59)</dd>
  37 <dt>bit4:0</dt>
  38 <dd>Second / 2 (0..29, e.g. 25 for 50)</dd>
  39 </dl>
  40 </div>
  41
  42
  43 <div class="para desc">
  44 <h4>Description</h4>
  45 <p>The <tt>get_fattime</tt> function shall return any valid time even if the system does not support a real time clock. If a zero is returned, the file will not have a valid timestamp.</p>
  46 </div>
  47
  48
  49 <div class="para comp">
  50 <h4>QuickInfo</h4>
  51 <p>This function is not needed when <tt><a href="config.html#fs_readonly">FF_FS_READONLY</a> == 1</tt> or <tt><a href="config.html#fs_nortc">FF_FS_NORTC</a> == 1</tt>.</p>
  52 </div>
  53
  54
  55 <div class="para use">
  56 <h4>Example</h4>
  57 <pre>
  58 DWORD get_fattime (void)
  59 {
  60     time_t t;
  61     struct tm *stm;
  62
  63
  64     t = time(0);
  65     stm = localtime(&t);
  66
  67     return (DWORD)(stm->tm_year - 80) &lt;&lt; 25 |
  68            (DWORD)(stm->tm_mon + 1) &lt;&lt; 21 |
  69            (DWORD)stm->tm_mday &lt;&lt; 16 |
  70            (DWORD)stm->tm_hour &lt;&lt; 11 |
  71            (DWORD)stm->tm_min &lt;&lt; 5 |
  72            (DWORD)stm->tm_sec &gt;&gt; 1;
  73 }
  74 </pre>
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