在刮刀数据之前改变src标签的值

大家好，我有这个代码:

foreach ($image as $snimka){
    $url = $snimka->src;
    $ch = curl_init($snimka->src);
    $fp = fopen('images/' . basename($url), 'wb');
    curl_setopt($ch, CURLOPT_FILE, $fp);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_exec($ch);
    curl_close($ch);
    fclose($fp);
    echo basename($url);
    echo '<br />';
}

这段代码工作完美，但在开始绘制图片以转移部分src之前，这就是我所想到的以下srcpartnersite.com/363-cart_default/kecove-nora-zhylto-i-sinio.jpg我想改变只是一个字从购物车变得大，然后才开始下载的图片怎么办，请帮助

我解决了我的问题，这是解决方案:

 foreach ($image as $snimka){
        $url = $snimka->src;
        $replace = preg_replace('~cart~','large',$url);
        $ch = curl_init($replace);
        $fp = fopen('images/' . basename($url), 'wb');
        curl_setopt($ch, CURLOPT_FILE, $fp);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_exec($ch);
        curl_close($ch);
        fclose($fp);
        echo basename($url);
        echo '<br />';
  }