PHP 디렉토리 함수 정리

/*
opendir, closedir
resource = opendir(string_path)
void closedir(resource_dir_handle)
http://php.net/manual/en/function.opendir.php
http://php.net/manual/en/function.closedir.php
*/
$dir = "../public_html/";
// 알고 있는 디렉토리를 열어서, 내용을 읽어들이는 작업입니다.
if (is_dir($dir)) {
    if ($dh = opendir($dir)) {
        while (($file = readdir($dh)) !== false) {
            echo "filename: $file : filetype: " . filetype($dir.$file);
        }
        closedir($dh);
    }
}

/*
readdir
string = readdir(resource_dir_hendle)
http://php.net/manual/en/function.readdir.php
*/
if ($handle = opendir('test/')) {
    echo "Directory handle : " . $handle;
    echo "Files : ";

    /* 디렉토리 안을 루프하는 올바른 방법입니다. */
    while (false !== ($file = readdir($handle))) {
        echo $file;
    }

    /* 디렉토리 안을 루프하는 *잘못된* 방법입니다. */
    while ($file = readdir($handle)) {
        echo $file;
    }

    closedir($handle); 
}

/*
rewinddir
void = rewinddir(resource_dir_handle)
http://php.net/manual/en/function.rewinddir.php
*/
if ($handle = opendir("test")) {
 // 1st
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // 2nd
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // 3rd
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // 4th
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // 5th
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // rewind dir
 rewinddir($handle);
 // go to 1st
 $filename = readdir($handle);
 echo " file name : " . $filename . "
";
 // close dir
 closedir($handle);
}

/*
chdir
bool = chdir(string_directory)
http://php.net/manual/en/function.chdir.php
*/
// 현재 디렉토리
echo getcwd();
// 바뀐 디렉토리
chdir('/public_html/test/');
echo getcwd();

/*
dir
Class dir(string directory)
http://php.net/manual/en/function.dir.php
*/
$d = dir("css");
echo "Handle: " . $d->handle . "
";
echo "Path: " . $d->path . "
";
while (false !== ($entry = $d->read())) {
   echo $entry."
";
}
$d->close();

/*
scandir
array = scandir(string_directory, int_sorting_order)
http://php.net/manual/en/function.scandir.php
*/
$dir    = 'css';
$files1 = scandir($dir); //asc
$files2 = scandir($dir, 1); // desc
print_r($files1);
print_r($files2);