php把微信图片链接保存到本地

<?php
$headimg = "http://thirdwx.qlogo.cn/mmopen/vi_32/CW96JibTBRccMbXlDhTm6bGbO7eXAwIqCP0UiaQukLnfyFaVs9PVM9gLS8libx2GuH2kz6bNfp2GZQccYKKFr5BCA/132";

/* PHP远程下载微信头像存到本地,本地图片转base64
 * $url 微信头像链接
 * $path 要保存图片的目录
 * $userid 用户唯一标识（用这个作为图片文件名，可以节省图片空间）
 */
function download_remote_pic($url,$path,$userid){
    $header = [
        'User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:45.0) Gecko/20100101 Firefox/45.0',
        'Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3',
        'Accept-Encoding: gzip, deflate',
    ];
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($curl, CURLOPT_ENCODING, 'gzip');
    curl_setopt($curl, CURLOPT_HTTPHEADER, $header);
    $data = curl_exec($curl);
    $code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
    curl_close($curl);
    if ($code == 200) {//把URL格式的图片转成base64_encode格式的！
        $imgBase64Code = "data:image/jpeg;base64," . base64_encode($data);
    }
    $img_content=$imgBase64Code;//图片内容
    if (preg_match('/^(data:\s*image\/(\w+);base64,)/', $img_content, $result)) {
        $type = $result[2];//得到图片类型png jpg gif
        //相对路径
        $relative_path=$path."/";
        //绝对路径（$_SERVER['DOCUMENT_ROOT']为网站根目录）
        $absolute_path = $_SERVER['DOCUMENT_ROOT'].$relative_path;
        if(!file_exists($absolute_path)){
            //检查是否有该文件夹，如果没有就创建，并给予最高权限
            mkdir($absolute_path,7777);
        }
        //文件名
        $filename=$userid.".{$type}";
        $new_file = $absolute_path.$filename;
        if (file_put_contents($new_file, base64_decode(str_replace($result[1], '', $img_content)))) {
            var_dump(222);
            return $relative_path.$filename;
        }else{
            var_dump(444);
            return false;
        }
    }else{
        var_dump(111);
        return false;
    }
}

//测试一下
$userid = 'img';
$file = $_SERVER['DOCUMENT_ROOT']."/upload/headimg/".$userid.".jpeg";
//判断头像是否存在，不存在就下载
if(!file_exists($file)){
    echo download_remote_pic($headimg,"/upload/headimg",$userid);
}