| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129 | <!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="alternate" hreflang="ja" title="Japanese" href="../ja/readdir.html"><link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default"><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></div><p class="foot"><a href="../00index_e.html">Return</a></p></body></html>
 |