Question

假设我想连接到FTP服务器，然后在活动模式下列出根目录（通过PORT命令）。为此，我将使用cURL库。

似乎cURL提供了这样的功能。有CURLOPT_FTPPORT选项，官方参考说明，端口可以选择后跟' - '来指定端口范围。

    if (CURL* curl = ::curl_easy_init())
    {
        guard.reset(curl, ::curl_easy_cleanup);

        ::curl_easy_setopt(curl, CURLOPT_URL, "ftp://10.0.0.162:21");
        ::curl_easy_setopt(curl, CURLOPT_FTPPORT, "localhost:37000-38000");

        CURLcode retval = ::curl_easy_perform(curl);
        if (retval != CURLE_OK)
        {
            throw NetworkError(retval, ::curl_easy_strerror(retval));
        }
    }

    ...

但这是一个问题。

如果范围中的第一个端口不可用，curl_easy_perform将失败并显示CURLE_FTP_PORT_FAILED。

修改

以详细模式输出：

* Rebuilt URL to: ftp://10.0.0.162:21/
* timeout on name lookup is not supported
*   Trying 10.0.0.162...
* Connected to 10.0.0.162 (10.0.0.162) port 21 (#0)
< 220 eugee-server / banner
> USER anonymous
< 331 Anonymous access allowed, send identity (e-mail name) as password.
> PASS ftp@example.com
< 230-Welcome to ftp.eugeeserver
< 230 User logged in.
> PWD
< 257 "/" is current directory.
* Entry path is '/'
* socket failure: Bad access
* Remembering we are in dir ""
* Connection #0 to host 10.0.0.162 left intact

PORT命令参数中的端口范围

0 个答案: