projects / z180-stamp.git / blame
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|---|---|---|
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1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">\r |
| 2 | <html lang="en">\r | |
| 3 | <head>\r | |
| 4 | <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">\r | |
| 5 | <meta http-equiv="Content-Style-Type" content="text/css">\r | |
| 6 | <link rel="up" title="FatFs" href="../00index_e.html">\r | |
| 7 | <link rel="alternate" hreflang="ja" title="Japanese" href="../ja/read.html">\r | |
| 8 | <link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">\r | |
| 9 | <title>FatFs - f_read</title>\r | |
| 10 | </head>\r | |
| 11 | \r | |
| 12 | <body>\r | |
| 13 | \r | |
| 14 | <div class="para func">\r | |
| 15 | <h2>f_read</h2>\r | |
| 16 | <p>The f_read function reads data from a file.</p>\r | |
| 17 | <pre>\r | |
| 18 | FRESULT f_read (\r | |
| 19 | FIL* <span class="arg">fp</span>, <span class="c">/* [IN] File object */</span>\r | |
| 20 | void* <span class="arg">buff</span>, <span class="c">/* [OUT] Buffer to store read data */</span>\r | |
| 21 | UINT <span class="arg">btr</span>, <span class="c">/* [IN] Number of bytes to read */</span>\r | |
| 22 | UINT* <span class="arg">br</span> <span class="c">/* [OUT] Number of bytes read */</span>\r | |
| 23 | );\r | |
| 24 | </pre>\r | |
| 25 | </div>\r | |
| 26 | \r | |
| 27 | <div class="para arg">\r | |
| 28 | <h4>Parameters</h4>\r | |
| 29 | <dl class="par">\r | |
| 30 | <dt>fp</dt>\r | |
| 31 | <dd>Pointer to the open file object.</dd>\r | |
| 32 | <dt>buff</dt>\r | |
| 33 | <dd>Pointer to the buffer to store read data.</dd>\r | |
| 34 | <dt>btr</dt>\r | |
| 35 | <dd>Number of bytes to read in range of <tt>UINT</tt> type.</dd>\r | |
| 36 | <dt>br</dt>\r | |
| 70702af1 | 37 | <dd>Pointer to the <tt>UINT</tt> variable to return number of bytes read. The value is always valid after the function call regardless of the result code.</dd>\r |
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38 | </dl>\r |
| 39 | </div>\r | |
| 40 | \r | |
| 41 | \r | |
| 42 | <div class="para ret">\r | |
| 43 | <h4>Return Values</h4>\r | |
| 44 | <p>\r | |
| 45 | <a href="rc.html#ok">FR_OK</a>,\r | |
| 46 | <a href="rc.html#de">FR_DISK_ERR</a>,\r | |
| 47 | <a href="rc.html#ie">FR_INT_ERR</a>,\r | |
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48 | <a href="rc.html#io">FR_INVALID_OBJECT</a>,\r |
| 49 | <a href="rc.html#tm">FR_TIMEOUT</a>\r | |
| 50 | </p>\r | |
| 51 | </div>\r | |
| 52 | \r | |
| 53 | \r | |
| 54 | <div class="para desc">\r | |
| 55 | <h4>Description</h4>\r | |
| 70702af1 | 56 | <p>The function starts to read data from the file at the position pointed by the read/write pointer. The read/write pointer advances as number of bytes read. After the function succeeded, <tt class="arg">*br</tt> should be checked to detect end of the file. In case of <tt class="arg">*br</tt> < <tt class="arg">btr</tt>, it means the read/write pointer reached end of the file during read operation.</p>\r |
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57 | </div>\r |
| 58 | \r | |
| 59 | \r | |
| 60 | <div class="para comp">\r | |
| 61 | <h4>QuickInfo</h4>\r | |
| 62 | <p>Always available.</p>\r | |
| 63 | </div>\r | |
| 64 | \r | |
| 65 | \r | |
| 66 | <div class="para ref">\r | |
| 67 | <h4>See Also</h4>\r | |
| 68 | <p><tt><a href="open.html">f_open</a>, <a href="gets.html">fgets</a>, <a href="write.html">f_write</a>, <a href="close.html">f_close</a>, <a href="sfile.html">FIL</a></tt></p>\r | |
| 69 | </div>\r | |
| 70 | \r | |
| 71 | <p class="foot"><a href="../00index_e.html">Return</a></p>\r | |
| 72 | </body>\r | |
| 73 | </html>\r |