91 lines
3.7 KiB
HTML
91 lines
3.7 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
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<html lang="en">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
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<meta http-equiv="Content-Style-Type" content="text/css">
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<link rel="up" title="FatFs" href="../00index_e.html">
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<link rel="alternate" hreflang="ja" title="Japanese" href="../ja/printf.html">
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<link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">
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<title>FatFs - f_printf</title>
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</head>
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<body>
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<div class="para func">
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<h2>f_printf</h2>
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<p>The f_printf function writes formatted string to the file.</p>
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<pre>
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int f_printf (
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FIL* <span class="arg">fp</span>, <span class="c">/* [IN] File object */</span>
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const TCHAR* <span class="arg">fmt</span>, <span class="c">/* [IN] Format stirng */</span>
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...
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);
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</pre>
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</div>
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<div class="para arg">
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<h4>Parameters</h4>
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<dl class="par">
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<dt>fp</dt>
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<dd>Pointer to the open file object structure.</dd>
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<dt>fmt</dt>
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<dd>Pointer to the null terminated format string.</dd>
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<dt>...</dt>
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<dd>Optional arguments.</dd>
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</dl>
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</div>
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<div class="para ret">
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<h4>Return Values</h4>
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<p>When the function succeeded, it returns number of characters written. When the function failed due to disk full or any error, an <tt>EOF (-1)</tt> will be returned.</p>
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</div>
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<div class="para desc">
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<h4>Description</h4>
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<p>The <tt>f_printf()</tt> is a wrapper function of <a href="write.html"><tt>f_write()</tt></a>. The format control directive is a sub-set of standard library shown as follos:</p>
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<ul>
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<li>Type: <tt>c C s S d D u U x X b B</tt></li>
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<li>Size: <tt>l L</tt></li>
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<li>Flag: <tt>0 -</tt></li>
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</ul>
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</div>
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<div class="para comp">
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<h4>QuickInfo</h4>
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<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>
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<p>When FatFs is configured to Unicode API (<tt>_LFN_UNICODE == 1</tt>), data types on the srting fuctions, <tt>f_putc()</tt>, <tt>f_puts()</tt>, <tt>f_printf()</tt> and <tt>f_gets()</tt>, is also switched to Unicode. The character encoding on the file to be read/written via those functions is selected by <tt>_STRF_ENCODE</tt> option.</p>
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</div>
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<div class="para use">
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<h4>Example</h4>
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<pre>
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f_printf(&fil, "%d", 1234); <span class="c">/* "1234" */</span>
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f_printf(&fil, "%6d,%3d%%", -200, 5); <span class="c">/* " -200, 5%" */</span>
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f_printf(&fil, "%-6u", 100); <span class="c">/* "100 " */</span>
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f_printf(&fil, "%ld", 12345678L); <span class="c">/* "12345678" */</span>
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f_printf(&fil, "%04x", 0xAB); <span class="c">/* "00ab" */</span>
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f_printf(&fil, "%08LX", 0x123ABCL); <span class="c">/* "00123ABC" */</span>
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f_printf(&fil, "%016b", 0x550F); <span class="c">/* "0101010100001111" */</span>
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f_printf(&fil, "%s", "String"); <span class="c">/* "String" */</span>
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f_printf(&fil, "%5s", "abc"); <span class="c">/* " abc" */</span>
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f_printf(&fil, "%-5s", "abc"); <span class="c">/* "abc " */</span>
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f_printf(&fil, "%c", 'a'); <span class="c">/* "a" */</span>
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f_printf(&fil, "%f", 10.0); <span class="c">/* f_printf lacks floating point support */</span>
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</pre>
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</div>
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<div class="para ref">
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<h4>See Also</h4>
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<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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</div>
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<p class="foot"><a href="../00index_e.html">Return</a></p>
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</body>
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</html>
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