?? getfree.html
字號:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta http-equiv="Content-Style-Type" content="text/css">
<link rel="up" title="FatFs" href="../00index_e.html">
<link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">
<title>FatFs - f_getfree</title>
</head>
<body>
<div class="para">
<h2>f_getfree</h2>
<p>The f_getfree function gets number of the free clusters.</p>
<pre>
FRESULT f_getfree (
const char* <em>Path</em>, /* Root directory of the drive */
DWORD* <em>Clusters</em>, /* Pointer to the variable to store number of free clusters */
FATFS** <em>FileSystemObject</em> /* Pointer to pointer to file system object */
);
</pre>
</div>
<div class="para">
<h4>Parameters</h4>
<dl class="par">
<dt>Path</dt>
<dd>Pinter to the null-terminated string that specifies the <a href="filename.html">root directory</a> of the logical drive. Always specify a null-string for Tiny-FatFs.</dd>
<dt>Clusters</dt>
<dd>Pointer to the DWORD variable to store number of free clusters.</dd>
<dt>FileSystemObject</dt>
<dd>Pointer to pointer that to store a pointer to the corresponding file system object.</dd>
</dl>
</div>
<div class="para">
<h4>Return Values</h4>
<dl class="ret">
<dt>FR_OK (0)</dt>
<dd>The function succeeded. The <tt><em>*Clusters</em></tt> has number of free clusters and <tt><em>*FileSystemObject</em></tt> points the file system object.</dd>
<dt>FR_INVALID_DRIVE</dt>
<dd>The drive number is invalid.</dd>
<dt>FR_NOT_READY</dt>
<dd>The disk drive cannot work due to no medium in the drive or any other reason.</dd>
<dt>FR_RW_ERROR</dt>
<dd>The function failed due to a disk error or an internal error.</dd>
<dt>FR_NOT_ENABLED</dt>
<dd>The logical drive has no work area.</dd>
<dt>FR_NO_FILESYSTEM</dt>
<dd>There is no valid FAT partition on the disk.</dd>
</dl>
</div>
<div class="para">
<h4>Descriptions</h4>
<p>The f_getfree function gets number of free clusters on the drive. The member <tt>csize</tt> in the file system object is refreting number of sectors per cluster, so that the free space in unit of sector can be calcurated with this. When <tt>_USE_FSINFO</tt> option is enabled, this function might return an inaccurate free cluster count on FAT32 volume. When it is disabled, this function will take a time on FAT32 volume.</p>
<p>This function is not supported in read-only configuration and minimization level of >= 1.</p>
</div>
<div class="para">
<h4>Example</h4>
<pre>
FATFS *fs;
DWORD clust;
// Get free clusters
res = f_getfree("", &clust, &fs);
if (res) die(res);
// Get free space
printf("%lu KB total disk space.\n"
"%lu KB available on the disk.\n",
(DWORD)(fs->max_clust - 2) * fs->csize / 2,
clust * fs->csize / 2);
</pre>
</div>
<div class="para">
<h4>References</h4>
<p><tt><a href="sfatfs.html">FATFS</a></tt></p>
</div>
<p class="foot"><a href="../00index_e.html">Return</a></p>
</body>
</html>
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -