PHP uses `curl` to download a file; if the download is successful, it returns the file path; if it fails, it returns a download link.

I've written about similar features before, but I didn't take notes at the time, so I eventually forgot about them. Recently, I've started writing about this again, so I'd like to record it here!

PHP code:

public function downloadFile($url, $path) {
    // 判断文件是否存在
    if (file_exists($path)) {
        // 判断文件大小是否大于10KB
        if (filesize($path) > 10240) {
            // 文件已经成功下载过
            return str_replace(dirname(dirname(__DIR__)), '', $path);
        }
    }
    // echo 123;
    // 初始化 cURL
    $ch = curl_init($url);

    // 设置保存文件路径及文件句柄
    $fp = fopen($path, 'w');
    curl_setopt($ch, CURLOPT_FILE, $fp);

    // 设置 cURL 选项
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
    curl_setopt($ch, CURLOPT_TIMEOUT, 60);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');

    // 执行下载
    $result = curl_exec($ch);

    // 关闭文件句柄和 cURL 资源
    fclose($fp);
    curl_close($ch);

    // 根据下载结果返回对应的值
    if ($result !== false) {
        return str_replace(dirname(dirname(__DIR__)), '', $path);
    } else {
        // 处理错误
        return $url;
    }
}

Code Usage:

Add it to your class library, then simply pass the download link and the absolute storage path as arguments; please make the necessary modifications to the code and update it accordingly. The code is provided for reference only.