Capture header from response

[mulderp]

Hello,

I would like to capture the header data from a response.
In the curl documentation I think it should be possible by using HEADERDATA and I found an example here:

https://gist.github.com/whoshuu/2dc858b8730079602044

However, with curlpp I was not sure how to apply this.
I tried:

  myRequest.setOpt(cURLpp::Options::HeaderFunction(f));

but not sure how to define f, and if there would be a similar way to write to stream like the normal response body:

myRequest.setOpt(cURLpp::Options::WriteStream(&resp));

[sgallou]

Hello,

you can use lambda, like to get the full header buffer :

std::string headersBuffer;
m_request.setOpt(curlpp::options::HeaderFunction(
   [&headersBuffer](char* ptr, size_t size, size_t nbItems)
   {
      const auto incomingSize = size * nbItems;
      headersBuffer.append(ptr, incomingSize);
      return incomingSize;
   }));

And you can use this function to organize the buffer as a map of header :

std::map<std::string, std::string> CCurlppHttpRestRequest::formatResponseHeaders(const std::string& headersBuffer) const
{
   std::vector<std::string> headerKeyValues;
   split(headerKeyValues, headersBuffer, boost::is_any_of("\n"), boost::algorithm::token_compress_on);

   std::map<std::string, std::string> responseHeaders;
   for (const auto& headerKeyValue : headerKeyValues)
   {
      const auto separatorIterator = headerKeyValue.find(':');
      if (separatorIterator == std::string::npos)
         continue;

      // Http headers are not case-sensitive
      // Make all lower to facilitate search and comparison

      auto key = headerKeyValue.substr(0, separatorIterator);
      boost::to_lower(key);

      auto value = headerKeyValue.substr(separatorIterator + 1, std::string::npos);
      boost::to_lower(value);

      responseHeaders[key] = value;
   }

   return responseHeaders;
}

Hope this help