在PHP中保存图像：图像未保存

Question

我正在尝试编写一个脚本来保存图像，它假设将图像保存在脚本位于磁盘的同一位置，但没有运气。我在这里错过了其他什么东西？

//Function to make GET request using cURL
function curlGet($url) {
    $ch = curl_init();  //Initialising cURL session
    //Setting cURL options
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_URL, $url);
    $results = curl_exec($ch);  //Executing cURL session
    curl_close($ch);    //Closing cURL session
    return $results;    //Return the results
}

//Function to return XPath object
function returnXPathObject($item) {
    $xmlPageDom = new DomDocument();    //Instanting a new DomDocument object
    @$xmlPageDom->loadHTML($item);  //Loading the HTML from downloaded page
    $xmlPageXPath = new DOMXPath($xmlPageDom);  //Instanting new XPath DOM object
    return $xmlPageXPath;   //Return XPath object
}

$packtPage = curlGet('http://www.packtpub.com/news/experience-amazing-gimp-photo-editing-tools-with-packts-new-ebook'); //Calling function curlGet and storing returned results in $packtPage variable

$packtPageXpath = returnXPathObject($packtPage);    //Instanting new XPath DOM object

$coverImage = $packtPageXpath->query('//span/img/@src');    //Querying for book cover image URL

//If cover image exist
if ($coverImage->length > 0) {

    $imageUrl = $coverImage->item(0)->nodeValue;    //Add URL to variable

    $imageName = end(explode('/', $imageUrl)); //Retrieving image name from URL

    //If file is an image
    if (getimagesize($imageUrl)) {
        $imageFile = curlGet($imageUrl);    //Download image using cURL
        $file = fopen($imageName, 'w'); //Opening file handle
        fwrite($file, $imageFile);  //Writing image file
        fclose($file);  //Closing file handle
    }
}