写一个函数，获取一篇文章内容中的全部图片，并下载

function download_images($article_url = '', $image_path = 'tmp'){

    // 获取文章类容
    $content = file_get_contents($article_url);

    // 利用正则表达式得到图片链接
    $reg_tag = '/<img.*?"([^"]*(jpg|bmp|jpeg|gif|png)).*?>/';
    $ret = preg_match_all($reg_tag, $content, $match_result); 
    $pic_url_array = array_unique($match_result1[1]);

    // 创建路径
    $dir = getcwd() . DIRECTORY_SEPARATOR .$image_path;
    mkdir(iconv("UTF-8", "GBK", $dir), 0777, true);

    foreach($pic_url_array as $pic_url){
        // 获取文件信息
        $ch = curl_init($pic_url);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_NOBODY, 0);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE );
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE );
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $fileInfo = curl_exec($ch);
        $httpinfo = curl_getinfo($ch);
        curl_close($ch);

        // 获取图片文件后缀
        $ext = strrchr($pic_url, '.');
        $filename = $dir . '/' . uniqid() . $ext; 

        // 保存图片信息到文件
        $local_file = fopen($filename, 'w');
        if(false !== $local_file){
            if( false !== fwrite($local_file, $filecontent) ){
            fclose($local_file);
            }
        }
    }

}