fatfs/documents/doc/findfirst.html

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   9 <title>FatFs - f_findfirst</title>
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  12 <body>
  13
  14 <div class="para func">
  15 <h2>f_findfirst</h2>
  16 <p>The f_findfirst function searches a directroy for an item.</p>
  17 <pre>
  18 FRESULT f_findfirst (
  19   DIR* <span class="arg">dp</span>,              <span class="c">/* [OUT] Poninter to the directory object */</span>
  20   FILINFO* <span class="arg">fno</span>,         <span class="c">/* [OUT] Pointer to the file information structure */</span>
  21   const TCHAR* <span class="arg">path</span>,    <span class="c">/* [IN] Pointer to the directory name to be opened */</span>
  22   const TCHAR* <span class="arg">pattern</span>  <span class="c">/* [IN] Pointer to the matching pattern string */</span>
  23 );
  24 </pre>
  25 </div>
  26
  27 <div class="para arg">
  28 <h4>Parameters</h4>
  29 <dl class="par">
  30 <dt>dp</dt>
  31 <dd>Pointer to the blank directory object.</dd>
  32 <dt>fno</dt>
  33 <dd>Pointer to the <a href="sfileinfo.html">file information structure</a> to store the information about the found item.</dd>
  34 <dt>path</dt>
  35 <dd>Pointer to the null-terminated string that specifies the <a href="filename.html">directory name</a> to be opened.</dd>
  36 <dt>pattern</dt>
  37 <dd>Pointer to the nul-terminated string that specifies the name matching pattern to be searched for. It is referred by also subsequent <tt>f_findnext</tt> function, so that the string must be valid while the successive function calls.</dd>
  38 </dl>
  39 </div>
  40
  41
  42 <div class="para ret">
  43 <h4>Return Values</h4>
  44 <p>
  45 <a href="rc.html#ok">FR_OK</a>,
  46 <a href="rc.html#de">FR_DISK_ERR</a>,
  47 <a href="rc.html#ie">FR_INT_ERR</a>,
  48 <a href="rc.html#nr">FR_NOT_READY</a>,
  49 <a href="rc.html#np">FR_NO_PATH</a>,
  50 <a href="rc.html#in">FR_INVALID_NAME</a>,
  51 <a href="rc.html#io">FR_INVALID_OBJECT</a>,
  52 <a href="rc.html#id">FR_INVALID_DRIVE</a>,
  53 <a href="rc.html#ne">FR_NOT_ENABLED</a>,
  54 <a href="rc.html#ns">FR_NO_FILESYSTEM</a>,
  55 <a href="rc.html#tm">FR_TIMEOUT</a>,
  56 <a href="rc.html#nc">FR_NOT_ENOUGH_CORE</a>,
  57 <a href="rc.html#tf">FR_TOO_MANY_OPEN_FILES</a>
  58 </p>
  59 </div>
  60
  61
  62 <div class="para desc">
  63 <h4>Description</h4>
  64 <p>After the directory specified by <tt class="arg">path</tt> could be opened, it starts to search the directory for items with the name specified by <tt class="arg">pattern</tt>. If the first item is found, the information about the object is stored into the file information structure <tt class="arg">fno</tt>.</p>
  65 <p>The matching pattern can contain wildcard characters (<tt>?</tt> and <tt>*</tt>). A <tt>?</tt> matches an any character and an <tt>*</tt> matches an any string in length of zero or longer. When support of long file name is enabled, only <tt>fname[]</tt> is tested at <tt>FF_USE_FIND == 1</tt> and also <tt>altname[]</tt> is tested at <tt>FF_USE_FIND == 2</tt>. In this revision, there are some differences listed below between FatFs and standard systems in matching condition.</p>
  66 <ul>
  67 <li><tt>"*.*"</tt> never matches any name without extension while it matches any name with or without extension at the standard systems.</li>
  68 <li>Any pattern terminated with a period never matches any name while it matches any name without extensiton at the standard systems.</li>
  69 <li><a href="filename.html#case">DBCS extended characters</a> are compared in case-sensitive at LFN with ANSI/OEM API.</li>
  70 </ul>
  71 </div>
  72
  73
  74 <div class="para comp">
  75 <h4>QuickInfo</h4>
  76 <p>This is a wrapper function of <a href="opendir.html"><tt>f_opendir</tt></a> and <a href="readdir.html"><tt>f_readdir</tt></a> function. Available when <tt><a href="config.html#use_find">FF_USE_FIND</a> &gt;= 1</tt> and <tt><a href="config.html#fs_minimize">FF_FS_MINIMIZE</a> &lt;= 1</tt>.</p>
  77 </div>
  78
  79
  80 <div class="para use">
  81 <h4>Examples</h4>
  82 <pre>
  83 <span class="c">/* Search a directory for objects and display it */</span>
  84
  85 void find_image_file (void)
  86 {
  87     FRESULT fr;     <span class="c">/* Return value */</span>
  88     DIR dj;         <span class="c">/* Directory search object */</span>
  89     FILINFO fno;    <span class="c">/* File information */</span>
  90
  91     fr = <em>f_findfirst</em>(&amp;dj, &amp;fno, "", "dsc*.jpg");  <span class="c">/* Start to search for photo files */</span>
  92
  93     while (fr == FR_OK &amp;&amp; fno.fname[0]) {         <span class="c">/* Repeat while an item is found */</span>
  94         printf("%s\n", fno.fname);                <span class="c">/* Display the object name */</span>
  95         fr = f_findnext(&amp;dj, &amp;fno);               <span class="c">/* Search for next item */</span>
  96     }
  97
  98     f_closedir(&amp;dj);
  99 }
 100 </pre>
 101 </div>
 102
 103
 104 <div class="para ref">
 105 <h4>See Also</h4>
 106 <p><tt><a href="findnext.html">f_findnext</a>, <a href="closedir.html">f_closedir</a>, <a href="sdir.html">DIR</a>, <a href="sfileinfo.html">FILINFO</a></tt></p>
 107 </div>
 108
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