c++ - 如何使用 libcurl 和 POP3 删除电子邮件？

Question

可以吗？我知道自定义请求；所以我发送带有文本“DELE”的自定义请求，并设置我要删除的消息 ID。结果，curl_easy_perform 挂起，直到出现超时。在网络论坛上，人们建议在“DELE”之后发送“QUIT”命令；但是如果 libcurl 挂起，我该如何发送“QUIT”命令呢？

libcurl 调试输出如下:

* Connected to pop-mail.outlook.com (157.55.1.215) port 995 (#2)
* SSL connection using DES-CBC3-SHA
* Server certificate:
*        subject: C=US; ST=Washington; L=Redmond; O=Microsoft Corporation; CN=*.
hotmail.com
*        start date: 2013-04-24 20:35:09 GMT
*        expire date: 2016-04-24 20:35:09 GMT
*        issuer: C=BE; O=GlobalSign nv-sa; CN=GlobalSign Organization Validation
 CA - G2
*        SSL certificate verify result: unable to get local issuer certificate (
20), continuing anyway.
< +OK DUB0-POP132 POP3 server ready
> CAPA
< -ERR unrecognized command
> USER ************@hotmail.com
< +OK password required
> PASS ******************
< +OK mailbox has 1 messages
> DELE 1
< +OK message deleted
* Operation too slow. Less than 1000 bytes/sec transferred the last 10 seconds
> QUIT
* Operation too slow. Less than 1000 bytes/sec transferred the last 10 seconds
* Closing connection 2

因此，消息被删除，但 libcurl 挂起，直到速度限制强制它断开连接，这是个坏主意。如何在删除消息后强制停止而不等到超时？

Answer 1

如果您查看 libcurl 文档，CURLOPT_CUSTOMREQUEST说:

POP3

When you tell libcurl to use a custom request it will behave like a LIST or RETR command was sent where it expects data to be returned by the server. As such CURLOPT_NOBODY should be used when specifying commands such as DELE and NOOP for example.

这就是 libcurl 挂起的原因 - 它正在等待服务器实际上没有发送的更多数据。所以添加 CURLOPT_NOBODY 来停止等待。