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<link rel="alternate" hreflang="ja" title="Japanese" href="../ja/readdir.html">
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<title>FatFs - f_readdir</title>
</head>
<body>
<div class="para func">
<h2>f_readdir</h2>
<p>The f_readdir function reads an item of the directory.</p>
<pre>
FRESULT f_readdir (
DIR* <span class="arg">dp</span>, <span class="c">/* [IN] Directory object */</span>
FILINFO* <span class="arg">fno</span> <span class="c">/* [OUT] File information structure */</span>
);
</pre>
</div>
<div class="para arg">
<h4>Parameters</h4>
<dl class="par">
<dt>dp</dt>
<dd>Pointer to the open directory object or null pointer.</dd>
<dt>fno</dt>
<dd>Pointer to the <a href="sfileinfo.html">file information structure</a> to store the information about read item.</dd>
</dl>
</div>
<div class="para ret">
<h4>Return Values</h4>
<p>
<a href="rc.html#ok">FR_OK</a>,
<a href="rc.html#de">FR_DISK_ERR</a>,
<a href="rc.html#ie">FR_INT_ERR</a>,
<a href="rc.html#io">FR_INVALID_OBJECT</a>,
<a href="rc.html#tm">FR_TIMEOUT</a>,
<a href="rc.html#nc">FR_NOT_ENOUGH_CORE</a>
</p>
</div>
<div class="para desc">
<h4>Description</h4>
<p>The <tt>f_readdir</tt> function reads a directory item, informations about the object. All items in the directory can be read in sequence by <tt>f_readdir</tt> function calls. Dot entries (<tt>"."</tt> and <tt>".."</tt>) in the sub-directory are filtered out and they will never appear in the read items. When all directory items have been read and no item to read, a nul string is stored into the <tt>fno->fname[]</tt> without any error. When a null pointer is given to the <tt class="arg">fno</tt>, the read index of the directory object is rewinded.</p>
<p>When support of long file name (LFN) is enabled, a member <tt>altname[]</tt> is defined in the file information structure to store the short file name of the object. In case of the some conditions listed below, short file name is stored into the <tt>fname[]</tt> and <tt>altname[]</tt> has a null string.</p>
<ul>
<li>The item has no long file name. (Not the case at exFAT volume)</li>
<li>Setting of <tt>_MAX_LFN</tt> is insufficient for the long file name. (Not the case at <tt>_MAX_LFN == 255</tt>)</li>
<li>The long file name contains any character not allowed in ANSI/OEM code. (Not the case at <tt>_LFN_UNICODE == 1</tt>)</li>
</ul>
<p>There is a problem on reading a directory of exFAT volume. The exFAT does not support short file name. This means no name can be returned on the condition above. If it is the case, a "?" is returned as file name to indicate that the object is not accessible. To avoid this problem, configure FatFs <tt>_LFN_UNICODE = 1</tt> and <tt>_MAX_LFN = 255</tt> to support the full feature of LFN specification.</p>
</div>
<div class="para comp">
<h4>QuickInfo</h4>
<p>Available when <tt>_FS_MINIMIZE <= 1</tt>.</p>
</div>
<div class="para use">
<h4>Sample Code</h4>
<pre>
FRESULT scan_files (
char* path <span class="c">/* Start node to be scanned (***also used as work area***) */</span>
)
{
FRESULT res;
DIR dir;
UINT i;
static FILINFO fno;
res = f_opendir(&dir, path); <span class="c">/* Open the directory */</span>
if (res == FR_OK) {
for (;;) {
res = f_readdir(&dir, &fno); <span class="c">/* Read a directory item */</span>
if (res != FR_OK || fno.fname[0] == 0) break; <span class="c">/* Break on error or end of dir */</span>
if (fno.fattrib & AM_DIR) { <span class="c">/* It is a directory */</span>
i = strlen(path);
sprintf(&path[i], "/%s", fno.fname);
res = scan_files(path); <span class="c">/* Enter the directory */</span>
if (res != FR_OK) break;
path[i] = 0;
} else { <span class="c">/* It is a file. */</span>
printf("%s/%s\n", path, fno.fname);
}
}
f_closedir(&dir)
}
return res;
}
int main (void)
{
FATFS fs;
FRESULT res;
char buff[256];
res = f_mount(&fs, "", 1);
if (res == FR_OK) {
strcpy(buff, "/");
res = scan_files(buff);
}
return res;
}
</pre>
</div>
<div class="para ref">
<h4>See Also</h4>
<p><tt><a href="opendir.html">f_opendir</a>, <a href="closedir.html">f_closedir</a>, <a href="stat.html">f_stat</a>, <a href="sfileinfo.html">FILINFO</a>, <a href="sdir.html">DIR</a></tt></p>
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<p class="foot"><a href="../00index_e.html">Return</a></p>
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