如何在 libcurl 中禁用 Expect 100 continue

Question

我正在使用 CURLOPT_POST 发送 https 消息。在运行过程中，我的应用程序卡在：

期望：100-继续

完成等待 100-继续

Answer 1

我今天早些时候刚遇到这个问题。我发现以下页面也讨论了它并建议如何禁用：

George's Log——当 curl 发送 100-continue

特别是您可以在放置/发布请求中设置一个空的“期望：”标头。我在 curl 的回调后教程中找到了一些示例代码，其中包含以下带有 DISABLE_EXPECT “打喷嚏”防护的代码段：

#ifdef DISABLE_EXPECT
/*
  Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue"
  header.  You can disable this header with CURLOPT_HTTPHEADER as usual.
  NOTE: if you want chunked transfer too, you need to combine these two
  since you can only set one list of headers with CURLOPT_HTTPHEADER. */ 

/* A less good option would be to enforce HTTP 1.0, but that might also
   have other implications. */ 
{
  struct curl_slist *chunk = NULL;

  chunk = curl_slist_append(chunk, "Expect:");
  res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
  /* use curl_slist_free_all() after the *perform() call to free this
     list again */ 
}
#endif

我保留了一个用于放置/发布请求的标头列表。将上述内容添加到该列表中的效果如广告所示：

// Disable Expect: 100-continue
vc->slist = curl_slist_append(vc->slist, "Expect:");
...
curl_easy_setopt(vc->curl, CURLOPT_HTTPHEADER, vc->slist);