[z180-stamp.git] / fatfs / doc / en / 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=iso-8859-1">\r
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<link rel="up" title="FatFs" href="../00index_e.html">\r
<link rel="alternate" hreflang="ja" title="Japanese" href="../ja/readdir.html">\r
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<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 directory entries.</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
</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 file information structure to store the read item.</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#nr">FR_NOT_READY</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 directory items, file and directory, in sequence. All items in the directory can be read by calling <tt>f_readdir()</tt> function repeatedly. When relative path feature is enabled (<tt>_FS_RPATH &gt;= 1</tt>), dot entries ("." and "..") are not filtered out and they will appear in the read items. When all directory items have been read and no item to read, a null string is returned into the <tt>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>\r
<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 use it. The <tt>lfname</tt> is a pointer to the LFN read buffer. The <tt>lfsize</tt> is size of the LFN read buffer in unit of <tt>TCHAR</tt>. If the LFN is not needed, set a null pointer to the <tt>lfname</tt> and the LFN is not returned. A null string will be returned into the LFN read buffer in case of following conditions.</p>\r
<ul>\r
<li>The directory item has no LFN information.</li>\r
<li>Either the size of read buffer or LFN working buffer is insufficient for the LFN.</li>\r
<li>The LFN contains any Unicode character that cannot be converted to OEM code. (not the case at Unicode API cfg.)</li>\r
</ul>\r
<p>When the directory item has no LFN information, lower case characters can be contained in the <tt>fname[]</tt>.</p>\r
</div>\r
\r
\r
<div class="para comp">\r
<h4>QuickInfo</h4>\r
<p>Available when <tt>_FS_MINIMIZE &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
    FILINFO fno;\r
    DIR dir;\r
    int i;\r
    char *fn;   <span class="c">/* This function is assuming non-Unicode cfg. */</span>\r
<span class="k">#if</span> _USE_LFN\r
    static char lfn[_MAX_LFN + 1];   <span class="c">/* Buffer to store the LFN */</span>\r
    fno.lfname = lfn;\r
    fno.lfsize = sizeof lfn;\r
<span class="k">#endif</span>\r
\r
\r
    res = f_opendir(&amp;dir, path);                       <span class="c">/* Open the directory */</span>\r
    if (res == FR_OK) {\r
        i = strlen(path);\r
        for (;;) {\r
            res = f_readdir(&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.fname[0] == '.') continue;             <span class="c">/* Ignore dot entry */</span>\r
<span class="k">#if</span> _USE_LFN\r
            fn = *fno.lfname ? fno.lfname : fno.fname;\r
<span class="k">#else</span>\r
            fn = fno.fname;\r
<span class="k">#endif</span>\r
            if (fno.fattrib &amp; AM_DIR) {                    <span class="c">/* It is a directory */</span>\r
                sprintf(&amp;path[i], "/%s", fn);\r
                res = scan_files(path);\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, fn);\r
            }\r
        }\r
        f_closedir(&amp;dir)\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
	4	<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">\r
	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
	16	<p>The f_readdir function reads directory entries.</p>\r
	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
	23	</div>\r
	24	\r
	25	<div class="para arg">\r
	26	<h4>Parameters</h4>\r
	27	<dl class="par">\r
	28	<dt>dp</dt>\r
	29	<dd>Pointer to the open directory object.</dd>\r
	30	<dt>fno</dt>\r
	31	<dd>Pointer to the file information structure to store the read item.</dd>\r
	32	</dl>\r
	33	</div>\r
	34	\r
	35	\r
	36	<div class="para ret">\r
	37	<h4>Return Values</h4>\r
	38	<p>\r
	39	<a href="rc.html#ok">FR_OK</a>,\r
	40	<a href="rc.html#de">FR_DISK_ERR</a>,\r
	41	<a href="rc.html#ie">FR_INT_ERR</a>,\r
	42	<a href="rc.html#nr">FR_NOT_READY</a>,\r
	43	<a href="rc.html#io">FR_INVALID_OBJECT</a>,\r
	44	<a href="rc.html#tm">FR_TIMEOUT</a>,\r
	45	<a href="rc.html#nc">FR_NOT_ENOUGH_CORE</a>\r
	46	</p>\r
	47	</div>\r
	48	\r
	49	\r
	50	<div class="para desc">\r
	51	<h4>Description</h4>\r
	52	<p>The <tt>f_readdir()</tt> function reads directory items, file and directory, in sequence. All items in the directory can be read by calling <tt>f_readdir()</tt> function repeatedly. When relative path feature is enabled (<tt>_FS_RPATH >= 1</tt>), dot entries ("." and "..") are not filtered out and they will appear in the read items. When all directory items have been read and no item to read, a null string is returned into the <tt>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>\r
	53	<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 use it. The <tt>lfname</tt> is a pointer to the LFN read buffer. The <tt>lfsize</tt> is size of the LFN read buffer in unit of <tt>TCHAR</tt>. If the LFN is not needed, set a null pointer to the <tt>lfname</tt> and the LFN is not returned. A null string will be returned into the LFN read buffer in case of following conditions.</p>\r
	54	<ul>\r
	55	<li>The directory item has no LFN information.</li>\r
	56	<li>Either the size of read buffer or LFN working buffer is insufficient for the LFN.</li>\r
	57	<li>The LFN contains any Unicode character that cannot be converted to OEM code. (not the case at Unicode API cfg.)</li>\r
	58	</ul>\r
	59	<p>When the directory item has no LFN information, lower case characters can be contained in the <tt>fname[]</tt>.</p>\r
	60	</div>\r
	61	\r
	62	\r
	63	<div class="para comp">\r
	64	<h4>QuickInfo</h4>\r
65	<p>Available when <tt>_FS_MINIMIZE <= 1</tt>.</p>\r
66	</div>\r
67	\r
68	\r
69	<div class="para use">\r
70	<h4>Sample Code</h4>\r
71	<pre>\r
72	FRESULT scan_files (\r
73	char* path <span class="c">/* Start node to be scanned (also used as work area) */</span>\r
74	)\r
75	{\r
76	FRESULT res;\r
77	FILINFO fno;\r
78	DIR dir;\r
79	int i;\r
80	char fn; <span class="c">/ This function is assuming non-Unicode cfg. */</span>\r
81	<span class="k">#if</span> _USE_LFN\r
82	static char lfn[_MAX_LFN + 1]; <span class="c">/* Buffer to store the LFN */</span>\r
83	fno.lfname = lfn;\r
84	fno.lfsize = sizeof lfn;\r
85	<span class="k">#endif</span>\r
86	\r
87	\r
88	res = f_opendir(&dir, path); <span class="c">/* Open the directory */</span>\r
89	if (res == FR_OK) {\r
90	i = strlen(path);\r
91	for (;;) {\r
92	res = f_readdir(&dir, &fno); <span class="c">/* Read a directory item */</span>\r
93	if (res != FR_OK \|\| fno.fname[0] == 0) break; <span class="c">/* Break on error or end of dir */</span>\r
94	if (fno.fname[0] == '.') continue; <span class="c">/* Ignore dot entry */</span>\r
95	<span class="k">#if</span> _USE_LFN\r
96	fn = *fno.lfname ? fno.lfname : fno.fname;\r
97	<span class="k">#else</span>\r
98	fn = fno.fname;\r
99	<span class="k">#endif</span>\r
100	if (fno.fattrib & AM_DIR) { <span class="c">/* It is a directory */</span>\r
101	sprintf(&path[i], "/%s", fn);\r
102	res = scan_files(path);\r
103	if (res != FR_OK) break;\r
104	path[i] = 0;\r
105	} else { <span class="c">/* It is a file. */</span>\r
106	printf("%s/%s\n", path, fn);\r
107	}\r
108	}\r
109	f_closedir(&dir)\r
110	}\r
111	\r
112	return res;\r
113	}\r
114	</pre>\r
115	</div>\r
116	\r
117	\r
118	<div class="para ref">\r
119	<h4>See Also</h4>\r
120	<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
121	</div>\r
122	\r
123	<p class="foot"><a href="../00index_e.html">Return</a></p>\r
124	</body>\r
125	</html>\r