SPL filterIterator

<?php
class RecursiveFileFilterIterator extends FilterIterator {
    // 满足条件的扩展名
    protected $ext = array('jpg','gif');
 
    /**
     * 提供 $path 并生成对应的目录迭代器
     */
    public function __construct($path) {
        parent::__construct(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path)));
    }
 
    /**
     * 检查文件扩展名是否满足条件
     */
    public function accept() {
        $item = $this->getInnerIterator();
        if ($item->isFile() && 
                in_array(pathinfo($item->getFilename(), PATHINFO_EXTENSION), $this->ext)) {
            return TRUE;
        }
    }
}
 
// 实例化
set_time_limit(0);
$i = 0;
foreach (new RecursiveFileFilterIterator('D:/') as $item) {
    echo ++$i.'、	'.$item . PHP_EOL.'<br/>';
}
?>