Usage instructions of php readdir() function

readdir() FunctionReturns the file name of the next file in the directory. Returns the entry name (file name) on success, or FALSE on failure.

Syntax

readdir(dir_handle);

Parameters	Description
##dir_handle	Optional. Specifies a directory handle resource previously opened by opendir(). If this parameter is not specified, the last link opened by opendir() is used.

readdir() Function example one, the code is as follows:

$dir = "readdir/"; 
 
// 判断是否为目录 
if (is_dir($dir)) { 
    if ($dh = opendir($dir)) { 
        while (($file = readdir($dh)) !== false) { 
            echo "filename: $file : filetype: " . filetype($dir . $file) . " "; 
        } 
        closedir($dh); 
    } 
}

readdir() Function example two, the code is as follows:

if ($handle = opendir('/path/to/files')) { 
    echo "Directory handle: $handle "; 
    echo "Files: "; 
 
    /* 这是正确地遍历目录方法 */ 
    while (false !== ($file = readdir($handle))) { 
        echo "$file "; 
    } 
 
    /* 这是错误地遍历目录的方法 */ 
    while ($file = readdir($handle)) { 
        echo "$file "; 
    } 
    closedir($handle); 
}

readdir() Function Example 3, readdir() will return . and .. entries. If you don’t want them, just filter them out. Example 2. List all files in the current directory and remove . and .., code As follows:

if ($handle = opendir('.')) { 
    while (false !== ($file = readdir($handle))) { 
        if ($file != "." && $file != "..") { 
            echo "$file "; 
        } 
    } 
    closedir($handle); 
}

Note:

readdir must be used in conjunction with opendir.

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