📄 readdir.html
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<title>FatFs - f_readdir</title>
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<div class="para">
<h2>f_readdir</h2>
<p>The f_readdir function reads directory entries.</p>
<pre>
FRESULT f_readdir (
DIR* <em>DirObject</em>, /* Pointer to the open directory object */
FILINFO* <em>FileInfo</em> /* Pointer to the file information structure */
);
</pre>
</div>
<div class="para">
<h4>Parameters</h4>
<dl class="par">
<dt>DirObject</dt>
<dd>Pointer to the open directory object.</dd>
<dt>FileInfo</dt>
<dd>Pointer to the file information structure to store the read item.</dd>
</dl>
</div>
<div class="para">
<h4>Return Values</h4>
<dl class="ret">
<dt>FR_OK (0)</dt>
<dd>The function succeeded.</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_DISK_ERR</dt>
<dd>The function failed due to an error in the disk function.</dd>
<dt>FR_INT_ERR</dt>
<dd>The function failed due to a wrong FAT structure or an internal error.</dd>
<dt>FR_INVALID_OBJECT</dt>
<dd>The directory object is invalid.</dd>
</dl>
</div>
<div class="para">
<h4>Description</h4>
<p>The f_readdir function reads directory entries in sequence. All items in the directory can be read by calling f_readdir function repeatedly. When all directory items have been read and no item to read, the function returns a null string into <tt>f_name[]</tt> member without any error. When a null pointer is given to the <tt>FileInfo</tt>, the read index of the directory object will be rewinded.</p>
<p>When LFN feature is enabled, <tt>lfname</tt> and <tt>lfsize</tt> in the file information structure must be initialized with valid value prior to calling the f_readdir function. The <tt>lfname</tt> is a pointer to the string buffer to return the long file name. The <tt>lfsize</tt> is the size of the string buffer. When either the size of specified buffer or LFN working buffer is insufficient to store the LFN or LFN is not exist, a null string will be returned. When <tt>lfname</tt> is a NULL, nothing is returned.</p>
<p>For details on the file informations, refer to the <tt>FILINFO</tt>. This function is not supported in minimization level of >=2.</p>
</div>
<div class="para">
<h4>Sample Code</h4>
<pre>
FRESULT scan_files (char* path)
{
FRESULT res;
FILINFO fno;
DIR dir;
int i;
char *fn;
#if _USE_LFN
static char lfn[_MAX_LFN * (_DF1S ? 2 : 1) + 1];
fno.lfname = lfn;
fno.lfsize = sizeof(lfn);
#endif
res = f_opendir(&dir, path);
if (res == FR_OK) {
i = strlen(path);
for (;;) {
res = f_readdir(&dir, &fno);
if (res != FR_OK || fno.fname[0] == 0) break;
#if _USE_LFN
fn = *fno.lfname ? fno.lfname : fno.fname;
#else
fn = fno.fname;
#endif
if (fno.fattrib & AM_DIR) {
sprintf(&path[i], "/%s", fn);
res = scan_files(path);
if (res != FR_OK) break;
path[i] = 0;
} else {
printf("%s/%s\n", path, fn);
}
}
}
return res;
}
</pre>
</div>
<div class="para">
<h4>References</h4>
<p><tt><a href="opendir.html">f_opendir</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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