FreeRTOS/Common/FileSystem/FatFs-0.7e/doc/en/printf.html

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   8 <title>FatFs - f_printf</title>
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  12
  13 <div class="para">
  14 <h2>f_printf</h2>
  15 <p>The f_printf function writes formatted string to the file.</p>
  16 <pre>
  17 int f_printf (
  18   FIL* <em>FileObject</em>,     /* File object */
  19   const char* <em>Foramt</em>,  /* Format stirng */
  20   ...
  21 );
  22 </pre>
  23 </div>
  24
  25 <div class="para">
  26 <h4>Parameters</h4>
  27 <dl class="par">
  28 <dt>FileObject</dt>
  29 <dd>Pointer to the open file object structure.</dd>
  30 <dt>Format</dt>
  31 <dd>Pointer to the null-terminated format string.</dd>
  32 <dt>...</dt>
  33 <dd>Optional arguments.</dd>
  34
  35 </dl>
  36 </div>
  37
  38
  39 <div class="para">
  40 <h4>Return Values</h4>
  41 <p>When the function succeeded, number of characters written is returned. When the function failed due to disk full or any error, an <tt>EOF</tt> will be returned.</p>
  42 </div>
  43
  44
  45 <div class="para">
  46 <h4>Description</h4>
  47 <p>The f_printf() is a wrapper function of <a href="putc.html">f_putc()</a> and <a href="puts.html">f_puts()</a>. The format control directive is a sub-set of standard library shown as follos:</p>
  48 <ul>
  49 <li>Type: <tt>c s d u X</tt></li>
  50 <li>Size: <tt>l</tt></li>
  51 <li>Flag: <tt>0</tt></li>
  52 </ul>
  53 </div>
  54
  55
  56 <div class="para">
  57 <h4>QuickInfo</h4>
  58 <p>Available when <tt>_FS_READONLY == 0</tt> and <tt>_USE_STRFUNC</tt> is 1 or 2. When it is set to 2, <tt>'\n'</tt>s contained in the output are converted to <tt>"\r\n"</tt>.</p>
  59 </div>
  60
  61
  62 <div class="para">
  63 <h4>Example</h4>
  64 <pre>
  65     f_printf(&amp;fil, "%6d", -200);         /* "  -200" */
  66     f_printf(&amp;fil, "%02u", 5);           /* "05" */
  67     f_printf(&amp;fil, "%ld", 12345678L);    /* "12345678" */
  68     f_printf(&amp;fil, "%08lX", 1194684UL);  /* "00123ABC" */
  69     f_printf(&amp;fil, "%s", "String");      /* "String" */
  70     f_printf(&amp;fil, "%c", 'a');           /* "a" */
  71 </pre>
  72 </div>
  73
  74
  75 <div class="para">
  76 <h4>See Also</h4>
  77 <p><tt><a href="open.html">f_open</a>, <a href="putc.html">f_putc</a>, <a href="puts.html">f_puts</a>, <a href="gets.html">f_gets</a>, <a href="close.html">f_close</a>, <a href="sfile.html">FIL</a></tt></p>
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