[z180-stamp.git] / fatfs / documents / doc / readdir.html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">\r
<html lang="en">\r
<head>\r
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">\r
<meta http-equiv="Content-Style-Type" content="text/css">\r
<link rel="up" title="FatFs" href="../00index_e.html">\r
<link rel="alternate" hreflang="ja" title="Japanese" href="../ja/readdir.html">\r
<link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">\r
<title>FatFs - f_readdir</title>\r
</head>\r
\r
<body>\r
\r
<div class="para func">\r
<h2>f_readdir</h2>\r
<p>The f_readdir function reads an item of the directory.</p>\r
<pre>\r
FRESULT f_readdir (\r
  DIR* <span class="arg">dp</span>,      <span class="c">/* [IN] Directory object */</span>\r
  FILINFO* <span class="arg">fno</span>  <span class="c">/* [OUT] File information structure */</span>\r
);\r
</pre>\r
<pre>\r
FRESULT f_rewinddir (\r
  DIR* <span class="arg">dp</span>       <span class="c">/* [IN] Directory object */</span>\r
);\r
</pre>\r
</div>\r
\r
<div class="para arg">\r
<h4>Parameters</h4>\r
<dl class="par">\r
<dt>dp</dt>\r
<dd>Pointer to the open directory object.</dd>\r
<dt>fno</dt>\r
<dd>Pointer to the <a href="sfileinfo.html">file information structure</a> to store the information about read item. A null pointer rewinds the read index of the directory.</dd>\r
</dl>\r
</div>\r
\r
\r
<div class="para ret">\r
<h4>Return Values</h4>\r
<p>\r
<a href="rc.html#ok">FR_OK</a>,\r
<a href="rc.html#de">FR_DISK_ERR</a>,\r
<a href="rc.html#ie">FR_INT_ERR</a>,\r
<a href="rc.html#io">FR_INVALID_OBJECT</a>,\r
<a href="rc.html#tm">FR_TIMEOUT</a>,\r
<a href="rc.html#nc">FR_NOT_ENOUGH_CORE</a>\r
</p>\r
</div>\r
\r
\r
<div class="para desc">\r
<h4>Description</h4>\r
<p>The <tt>f_readdir</tt> function reads a directory item, informations about the object, from the open directory. Items in the directory can be read in sequence by <tt>f_readdir</tt> function calls. When all items in the directory have been read and no item to read, a null string is stored into the <tt>fno-&gt;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. The <tt>f_rewinddir</tt> function is implemented as a macro.</p>\r
<pre>\r
#define <em>f_rewinddir</em>(dp) f_readdir((dp), 0)\r
</pre>\r
<p>When LFN is enabled, a member <tt>altname[]</tt> is defined in the file information structure to store the short file name of the object. If the long file name is not accessible due to a reason listed below, short file name is stored to the <tt>fname[]</tt> and the <tt>altname[]</tt> has a null string.</p>\r
<ul>\r
<li>The item has no LFN. (Not the case in exFAT volume)</li>\r
<li><a href="config.html#max_lfn"><tt>FF_MAX_LFN</tt></a> is insufficient to handle the LFN. (Not the case in <tt>FF_MAX_LFN == 255</tt>)</li>\r
<li><a href="config.html#lfn_buf"><tt>FF_LFN_BUF</tt></a> is insufficient to store the LFN.</li>\r
<li>The LFN contains some character not defined in current CP. (Not the case in <tt>FF_LFN_UNICODE != 0</tt>)</li>\r
</ul>\r
<p>There is an issue on read directories in 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, "?" is returned as the file name to indicate that the object is not accessible. To avoid this problem, configure FatFs <tt><a href="config.html#lfn_unicode">FF_LFN_UNICODE</a> != 0</tt> and <tt>FF_MAX_LFN == 255</tt> to support the full feature of LFN specification.</p>\r
<p>Dot entries (<tt>"."</tt> and <tt>".."</tt>) in the sub-directory of FAT volume are filtered out and they will never appear in the read items because exFAT lacks dot entries in the sub-directory.</p>\r
</div>\r
\r
\r
<div class="para comp">\r
<h4>QuickInfo</h4>\r
<p>Available when <tt><a href="config.html#fs_minimize">FF_FS_MINIMIZE</a> &lt;= 1</tt>.</p>\r
</div>\r
\r
\r
<div class="para use">\r
<h4>Sample Code</h4>\r
<pre>\r
FRESULT scan_files (\r
    char* path        <span class="c">/* Start node to be scanned (***also used as work area***) */</span>\r
)\r
{\r
    FRESULT res;\r
    DIR dir;\r
    UINT i;\r
    static FILINFO fno;\r
\r
\r
    res = f_opendir(&amp;dir, path);                       <span class="c">/* Open the directory */</span>\r
    if (res == FR_OK) {\r
        for (;;) {\r
            res = <em>f_readdir</em>(&amp;dir, &amp;fno);                   <span class="c">/* Read a directory item */</span>\r
            if (res != FR_OK || fno.fname[0] == 0) break;  <span class="c">/* Break on error or end of dir */</span>\r
            if (fno.fattrib &amp; AM_DIR) {                    <span class="c">/* It is a directory */</span>\r
                i = strlen(path);\r
                sprintf(&amp;path[i], "/%s", fno.fname);\r
                res = scan_files(path);                    <span class="c">/* Enter the directory */</span>\r
                if (res != FR_OK) break;\r
                path[i] = 0;\r
            } else {                                       <span class="c">/* It is a file. */</span>\r
                printf("%s/%s\n", path, fno.fname);\r
            }\r
        }\r
        f_closedir(&amp;dir);\r
    }\r
\r
    return res;\r
}\r
\r
\r
int main (void)\r
{\r
    FATFS fs;\r
    FRESULT res;\r
    char buff[256];\r
\r
\r
    res = f_mount(&amp;fs, "", 1);\r
    if (res == FR_OK) {\r
        strcpy(buff, "/");\r
        res = scan_files(buff);\r
    }\r
\r
    return res;\r
}\r
</pre>\r
</div>\r
\r
\r
<div class="para ref">\r
<h4>See Also</h4>\r
<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>\r
</div>\r
\r
<p class="foot"><a href="../00index_e.html">Return</a></p>\r
</body>\r
</html>\r
Commit	Line	Data
53668523 L	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
289f6a14	4	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">\r
53668523 L	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/readdir.html">\r
	8	<link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default">\r
	9	<title>FatFs - f_readdir</title>\r
	10	</head>\r
	11	\r
	12	<body>\r
	13	\r
	14	<div class="para func">\r
	15	<h2>f_readdir</h2>\r
70702af1	16	<p>The f_readdir function reads an item of the directory.</p>\r
53668523 L	17	<pre>\r
	18	FRESULT f_readdir (\r
	19	DIR* <span class="arg">dp</span>, <span class="c">/* [IN] Directory object */</span>\r
	20	FILINFO* <span class="arg">fno</span> <span class="c">/* [OUT] File information structure */</span>\r
	21	);\r
	22	</pre>\r
5630b930 L	23	<pre>\r
	24	FRESULT f_rewinddir (\r
	25	DIR* <span class="arg">dp</span> <span class="c">/* [IN] Directory object */</span>\r
	26	);\r
	27	</pre>\r
53668523 L	28	</div>\r
	29	\r
	30	<div class="para arg">\r
	31	<h4>Parameters</h4>\r
	32	<dl class="par">\r
	33	<dt>dp</dt>\r
289f6a14	34	<dd>Pointer to the open directory object.</dd>\r
53668523	35	<dt>fno</dt>\r
289f6a14	36	<dd>Pointer to the <a href="sfileinfo.html">file information structure</a> to store the information about read item. A null pointer rewinds the read index of the directory.</dd>\r
53668523 L	37	</dl>\r
	38	</div>\r
	39	\r
	40	\r
	41	<div class="para ret">\r
	42	<h4>Return Values</h4>\r
	43	<p>\r
	44	<a href="rc.html#ok">FR_OK</a>,\r
	45	<a href="rc.html#de">FR_DISK_ERR</a>,\r
	46	<a href="rc.html#ie">FR_INT_ERR</a>,\r
53668523 L	47	<a href="rc.html#io">FR_INVALID_OBJECT</a>,\r
	48	<a href="rc.html#tm">FR_TIMEOUT</a>,\r
	49	<a href="rc.html#nc">FR_NOT_ENOUGH_CORE</a>\r
	50	</p>\r
	51	</div>\r
	52	\r
	53	\r
	54	<div class="para desc">\r
	55	<h4>Description</h4>\r
5630b930 L	56	<p>The <tt>f_readdir</tt> function reads a directory item, informations about the object, from the open directory. Items in the directory can be read in sequence by <tt>f_readdir</tt> function calls. When all items in the directory have been read and no item to read, a null 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. The <tt>f_rewinddir</tt> function is implemented as a macro.</p>\r
	57	<pre>\r
	58	#define <em>f_rewinddir</em>(dp) f_readdir((dp), 0)\r
	59	</pre>\r
	60	<p>When LFN is enabled, a member <tt>altname[]</tt> is defined in the file information structure to store the short file name of the object. If the long file name is not accessible due to a reason listed below, short file name is stored to the <tt>fname[]</tt> and the <tt>altname[]</tt> has a null string.</p>\r
53668523	61	<ul>\r
5630b930 L	62	<li>The item has no LFN. (Not the case in exFAT volume)</li>\r
	63	<li><a href="config.html#max_lfn"><tt>FF_MAX_LFN</tt></a> is insufficient to handle the LFN. (Not the case in <tt>FF_MAX_LFN == 255</tt>)</li>\r
	64	<li><a href="config.html#lfn_buf"><tt>FF_LFN_BUF</tt></a> is insufficient to store the LFN.</li>\r
	65	<li>The LFN contains some character not defined in current CP. (Not the case in <tt>FF_LFN_UNICODE != 0</tt>)</li>\r
53668523	66	</ul>\r
5630b930 L	67	<p>There is an issue on read directories in 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, "?" is returned as the file name to indicate that the object is not accessible. To avoid this problem, configure FatFs <tt><a href="config.html#lfn_unicode">FF_LFN_UNICODE</a> != 0</tt> and <tt>FF_MAX_LFN == 255</tt> to support the full feature of LFN specification.</p>\r
5630b930 L	68	<p>Dot entries (<tt>"."</tt> and <tt>".."</tt>) in the sub-directory of FAT volume are filtered out and they will never appear in the read items because exFAT lacks dot entries in the sub-directory.</p>\r
53668523 L	69	</div>\r
	70	\r
	71	\r
	72	<div class="para comp">\r
	73	<h4>QuickInfo</h4>\r
289f6a14	74	<p>Available when <tt><a href="config.html#fs_minimize">FF_FS_MINIMIZE</a> <= 1</tt>.</p>\r
53668523 L	75	</div>\r
	76	\r
	77	\r
	78	<div class="para use">\r
	79	<h4>Sample Code</h4>\r
	80	<pre>\r
	81	FRESULT scan_files (\r
70702af1	82	char* path <span class="c">/* Start node to be scanned (*also used as work area) /</span>\r
53668523 L	83	)\r
	84	{\r
	85	FRESULT res;\r
53668523	86	DIR dir;\r
70702af1 L	87	UINT i;\r
70702af1 L	88	static FILINFO fno;\r
53668523 L	89	\r
	90	\r
	91	res = f_opendir(&dir, path); <span class="c">/* Open the directory */</span>\r
	92	if (res == FR_OK) {\r
53668523	93	for (;;) {\r
289f6a14	94	res = <em>f_readdir</em>(&dir, &fno); <span class="c">/* Read a directory item */</span>\r
53668523	95	if (res != FR_OK \|\| fno.fname[0] == 0) break; <span class="c">/* Break on error or end of dir */</span>\r
53668523	96	if (fno.fattrib & AM_DIR) { <span class="c">/* It is a directory */</span>\r
70702af1 L	97	i = strlen(path);\r
	98	sprintf(&path[i], "/%s", fno.fname);\r
	99	res = scan_files(path); <span class="c">/* Enter the directory */</span>\r
7b78a5a2	100	if (res != FR_OK) break;\r
70702af1	101	path[i] = 0;\r
53668523	102	} else { <span class="c">/* It is a file. */</span>\r
70702af1	103	printf("%s/%s\n", path, fno.fname);\r
53668523 L	104	}\r
53668523 L	105	}\r
5630b930	106	f_closedir(&dir);\r
53668523 L	107	}\r
	108	\r
	109	return res;\r
	110	}\r
70702af1 L	111	\r
	112	\r
	113	int main (void)\r
	114	{\r
	115	FATFS fs;\r
	116	FRESULT res;\r
	117	char buff[256];\r
	118	\r
	119	\r
	120	res = f_mount(&fs, "", 1);\r
	121	if (res == FR_OK) {\r
	122	strcpy(buff, "/");\r
	123	res = scan_files(buff);\r
	124	}\r
	125	\r
	126	return res;\r
	127	}\r
53668523 L	128	</pre>\r
	129	</div>\r
	130	\r
	131	\r
	132	<div class="para ref">\r
	133	<h4>See Also</h4>\r
	134	<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>\r
	135	</div>\r
	136	\r
	137	<p class="foot"><a href="../00index_e.html">Return</a></p>\r
	138	</body>\r
	139	</html>\r