projects / z180-stamp.git / blame
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| 289f6a14 L |
1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> |
| 2 | <html lang="en"> | |
| 3 | <head> | |
| 4 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> | |
| 5 | <meta http-equiv="Content-Style-Type" content="text/css"> | |
| 6 | <link rel="up" title="FatFs" href="../00index_e.html"> | |
| 7 | <link rel="alternate" hreflang="ja" title="Japanese" href="../ja/printf.html"> | |
| 8 | <link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default"> | |
| 9 | <title>FatFs - f_printf</title> | |
| 10 | </head> | |
| 11 | ||
| 12 | <body> | |
| 13 | ||
| 14 | <div class="para func"> | |
| 15 | <h2>f_printf</h2> | |
| 16 | <p>The f_printf function writes formatted string to the file.</p> | |
| 17 | <pre> | |
| 18 | int f_printf ( | |
| 19 | FIL* <span class="arg">fp</span>, <span class="c">/* [IN] File object */</span> | |
| 20 | const TCHAR* <span class="arg">fmt</span>, <span class="c">/* [IN] Format stirng */</span> | |
| 21 | ... | |
| 22 | ); | |
| 23 | </pre> | |
| 24 | </div> | |
| 25 | ||
| 26 | <div class="para arg"> | |
| 27 | <h4>Parameters</h4> | |
| 28 | <dl class="par"> | |
| 29 | <dt>fp</dt> | |
| 30 | <dd>Pointer to the open file object structure.</dd> | |
| 31 | <dt>fmt</dt> | |
| 32 | <dd>Pointer to the null <tt>'\0'</tt> terminated format string. The terminator character will not be output.</dd> | |
| 33 | <dt>...</dt> | |
| 34 | <dd>Optional arguments...</dd> | |
| 35 | ||
| 36 | </dl> | |
| 37 | </div> | |
| 38 | ||
| 39 | ||
| 40 | <div class="para ret"> | |
| 41 | <h4>Return Values</h4> | |
| 5630b930 | 42 | <p>When the string was written successfuly, it returns number of character encoding units written to the file. When the function failed due to disk full or an error, a negative value will be returned.</p> |
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43 | </div> |
| 44 | ||
| 45 | ||
| 46 | <div class="para desc"> | |
| 47 | <h4>Description</h4> | |
| 48 | <p>The format control directive is a sub-set of standard library shown as follows:</p> | |
| 49 | <pre> | |
| 5630b930 | 50 | %[flag][width][precision][size]type |
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51 | </pre> |
| 52 | <dl> | |
| 5630b930 L |
53 | <dt>flag</dt><dd>Padding option. A <tt>-</tt> specifies left-aligned. A <tt>0</tt> specifies zero padded. The default setting is in right-aligned and space padded.</dd> |
| 54 | <dt>width</dt><dd>Minimum width of the field, <tt>1-99</tt> or <tt>*</tt>. If the width of generated string is less than the minimum width, rest field is padded with spaces or zeros. An <tt>*</tt> specifies the value comes from an argument in int type. The default setting is zero.</dd> | |
| 55 | <dt>precision</dt><dd>Specifies number of fractional digits or maximum width of string, <tt>.0-.99</tt> or <tt>.*</tt>. If the number is omitted, it is same as <tt>.0</tt>. Default setting is 6 for number and no limit for string.</dd> | |
| 56 | <dt>size</dt><dd>Specifies size of integer argument, <tt>l</tt>(long) and <tt>ll</tt>(long long). If <tt>sizeof (long) == sizeof (int)</tt> is true (this is typical of 32-bit systems), prefix <tt>l</tt> can be omitted for long integer argument. The default size is int for integer argument and floating point argument is always assumed double as the default argument promotion.</dd> | |
| 57 | <dt>type</dt><dd>Specifies type of the output format and the argument as shown below. The length of generated string is in assumtion of int is 32-bit. | |
| 58 | <table class="lst1"> | |
| 59 | <tr><th>Type</th><th>Format</th><th>Argument</th><th>Length</th></tr> | |
| 60 | <tr><td><tt>c</tt></td><td>Character</td><td rowspan="6"><tt>int</tt>,<br><tt>long</tt>,<br><tt>long long</tt></td><td>1 character.</td></tr> | |
| 61 | <tr><td><tt>d</tt></td><td>Signed decimal</td><td>1 to 11 (20 for ll) characters.</td></tr> | |
| 62 | <tr><td><tt>u</tt></td><td>Unsigned decimal</td><td>1 to 10 (20 for ll) characters.</td></tr> | |
| 63 | <tr><td><tt>o</tt></td><td>Unsigned octal</td><td>1 to 11 (22 for ll) characters.</td></tr> | |
| 64 | <tr><td><tt>x X</tt></td><td>Unsigned hexdecimal</td><td>1 to 8 (16 for ll) characters.</td></tr> | |
| 65 | <tr><td><tt>b</tt></td><td>Unsigned binary</td><td>1 to 32 characters. Limited to lower 32 digits when ll is specified.</td></tr> | |
| 66 | <tr><td><tt>s</tt></td><td>String</td><td><tt>TCHAR*</tt></td><td>As input string. Null pointer generates a null string.</td></tr> | |
| 67 | <tr><td><tt>f</tt></td><td>Floating point<br>(decimal)</td><td rowspan="2"><tt>double</tt></td><td>1 to 31 characters. If the number of characters exceeds 31, it writes <tt>"±OV"</tt>. Not a number and infinite write <tt>"NaN"</tt> and <tt>"±INF"</tt>.</td></tr> | |
| 68 | <tr><td><tt>e E</tt></td><td>Floating point<br>(e notation)</td><td>4 to 31 characters. If the number of characters exceeds 31 or exponent exceeds +99, it writes <tt>"±OV"</tt>.</td></tr> | |
| 69 | </table> | |
| 70 | </dd> | |
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71 | </dl> |
| 72 | <p>When FatFs is configured for Unicode API (<tt><a href="config.html#lfn_unicode">FF_LFN_UNICODE</a> >= 1</tt>), character encoding on the string fuctions, <tt>f_putc</tt>, <tt>f_puts</tt>, <tt>f_printf</tt> and <tt>f_gets</tt> function, is also switched to Unicode. The Unicode characters in multiple encoding unit, such as surrogate pair and multi-byte sequence, should not be divided into two function calls, or the character will be lost. The character encoding <em>on the file</em> to be written via this function is selected by <tt><a href="config.html#strf_encode">FF_STRF_ENCODE</a></tt>. The characters with wrong encoding or invalid for the output encoding will be lost.</p> | |
| 5630b930 | 73 | <p>If <tt>sprintf</tt> is used in the project and code conversion is not needed, <tt>f_write</tt> with <tt>sprintf</tt> will be efficient in code size and performance rather than <tt>f_printf</tt>.</p> |
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74 | </div> |
| 75 | ||
| 76 | ||
| 77 | <div class="para comp"> | |
| 78 | <h4>QuickInfo</h4> | |
| 79 | <p>This is a wrapper function of <a href="write.html"><tt>f_write</tt></a> function. Available when <tt><a href="config.html#fs_readonly">FF_FS_READONLY</a> == 0</tt> and <tt><a href="config.html#use_strfunc">FF_USE_STRFUNC</a> >= 1</tt>. When <tt>FF_USE_STRFUNC == 2</tt>, <tt>'\n'</tt>s in the generated string are written as <tt>'\r'+'\n'</tt> each.</p> | |
| 80 | </div> | |
| 81 | ||
| 82 | ||
| 83 | <div class="para use"> | |
| 84 | <h4>Example</h4> | |
| 85 | <pre> | |
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86 | <em>f_printf</em>(fp, "%d", 1234); <span class="c">/* "1234" */</span> |
| 87 | <em>f_printf</em>(fp, "%6d,%3d%%", -200, 5); <span class="c">/* " -200, 5%" */</span> | |
| 88 | <em>f_printf</em>(fp, "%-6u", 100); <span class="c">/* "100 " */</span> | |
| 89 | <em>f_printf</em>(fp, "%ld", 12345678); <span class="c">/* "12345678" */</span> | |
| 90 | <em>f_printf</em>(fp, "%llu", 0x100000000); <span class="c">/* "4294967296" (<a href="config.html#print_lli">FF_PRINT_LLI</a>) */</span> | |
| 91 | <em>f_printf</em>(fp, "%lld", -1LL); <span class="c">/* "-1" (FF_PRINT_LLI) */</span> | |
| 92 | <em>f_printf</em>(fp, "%04x", 0xA3); <span class="c">/* "00a3" */</span> | |
| 93 | <em>f_printf</em>(fp, "%08lX", 0x123ABC); <span class="c">/* "00123ABC" */</span> | |
| 94 | <em>f_printf</em>(fp, "%016b", 0x550F); <span class="c">/* "0101010100001111" */</span> | |
| 95 | <em>f_printf</em>(fp, "%*d", 6, 100); <span class="c">/* " 100" */</span> | |
| 96 | <em>f_printf</em>(fp, "%s", "abcdefg"); <span class="c">/* "abcdefg" */</span> | |
| 97 | <em>f_printf</em>(fp, "%5s", "abc"); <span class="c">/* " abc" */</span> | |
| 98 | <em>f_printf</em>(fp, "%-5s", "abc"); <span class="c">/* "abc " */</span> | |
| 99 | <em>f_printf</em>(fp, "%.5s", "abcdefg"); <span class="c">/* "abcde" */</span> | |
| 100 | <em>f_printf</em>(fp, "%-5.2s", "abcdefg"); <span class="c">/* "ab " */</span> | |
| 101 | <em>f_printf</em>(fp, "%c", 'a'); <span class="c">/* "a" */</span> | |
| 102 | <em>f_printf</em>(fp, "%12f", 10.0); <span class="c">/* " 10.000000" (<a href="config.html#print_fp">FF_PRINT_FLOAT</a>) */</span> | |
| 103 | <em>f_printf</em>(fp, "%.4E", 123.45678); <span class="c">/* "1.2346E+02" (FF_PRINT_FLOAT) */</span> | |
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104 | </pre> |
| 105 | </div> | |
| 106 | ||
| 107 | ||
| 108 | <div class="para ref"> | |
| 109 | <h4>See Also</h4> | |
| 110 | <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> | |
| 111 | </div> | |
| 112 | ||
| 113 | <p class="foot"><a href="../00index_e.html">Return</a></p> | |
| 114 | </body> | |
| 115 | </html> |