request_stream << "Content-Type: application/x-www-form-urlencoded\r\n";

request_stream << "Content-Type: text/html\r\n";

#include <iostream>

#include <istream>

#include <ostream>

#include <string>

#include <boost/asio.hpp>

using boost::asio::ip::tcp;

using std::string;

int post_form(const string& host, const string& port, const string& page, const string& data, string& reponse_data)

{

  try

  {

    boost::asio::io_service io_service;

    //如果io_service存在复用的情况

    if(io_service.stopped())

      io_service.reset();

    // 从dns取得域名下的所有ip

    tcp::resolver resolver(io_service);

    tcp::resolver::query query(host, port);

    tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);

    // 尝试连接到其中的某个ip直到成功

    tcp::socket socket(io_service);

    boost::asio::connect(socket, endpoint_iterator); 

    // Form the request. We specify the "Connection: close" header so that the

    // server will close the socket after transmitting the response. This will

    // allow us to treat all data up until the EOF as the content.

    boost::asio::streambuf request;

    std::ostream request_stream(&request);

    request_stream << "POST " << page << " HTTP/1.0\r\n";

    request_stream << "Host: " << host << ":" << port << "\r\n";

    request_stream << "Accept: */*\r\n";

    request_stream << "Content-Length: " << data.length() << "\r\n";

    request_stream << "Content-Type: application/x-www-form-urlencoded\r\n";

    request_stream << "Connection: close\r\n\r\n";

    request_stream << data;

    // Send the request.

    boost::asio::write(socket, request);

    // Read the response status line. The response streambuf will automatically

    // grow to accommodate the entire line. The growth may be limited by passing

    // a maximum size to the streambuf constructor.

    boost::asio::streambuf response;

    boost::asio::read_until(socket, response, "\r\n");

    // Check that response is OK.

    std::istream response_stream(&response);

    std::string http_version;

    response_stream >> http_version;

    unsigned int status_code;

    response_stream >> status_code;

    std::string status_message;

    std::getline(response_stream, status_message);

    if (!response_stream || http_version.substr(, ) != "HTTP/")

    {

      reponse_data = "Invalid response";

      return -;

    }

    // 如果服务器返回非200都认为有错,不支持301/302等跳转

    if (status_code != )

    {

      reponse_data = "Response returned with status code != 200 " ;

      return status_code;

    }

    // 传说中的包头可以读下来了

    std::string header;

    std::vector<string> headers;

    while (std::getline(response_stream, header) && header != "\r")

      headers.push_back(header);

    // 读取所有剩下的数据作为包体

    boost::system::error_code error;

    while (boost::asio::read(socket, response,

        boost::asio::transfer_at_least(), error))

    {

    }

    //响应有数据

    if (response.size())

    {

      std::istream response_stream(&response);

      std::istreambuf_iterator<char> eos;

      reponse_data = string(std::istreambuf_iterator<char>(response_stream), eos);

    }

    if (error != boost::asio::error::eof)

    {

      reponse_data = error.message();

      return -;

    }

  }

  catch(std::exception& e)

  {

    reponse_data = e.what();

      return -;

  }

  return ;

}

int post_txt(const string& host, const string& port, const string& page, const string& data, string& reponse_data)

{

  try

  {

    boost::asio::io_service io_service;

    //如果io_service存在复用的情况

    if(io_service.stopped())

      io_service.reset();

    // 从dns取得域名下的所有ip

    tcp::resolver resolver(io_service);

    tcp::resolver::query query(host, port);

    tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);

    // 尝试连接到其中的某个ip直到成功

    tcp::socket socket(io_service);

    boost::asio::connect(socket, endpoint_iterator); 

    // Form the request. We specify the "Connection: close" header so that the

    // server will close the socket after transmitting the response. This will

    // allow us to treat all data up until the EOF as the content.

    boost::asio::streambuf request;

    std::ostream request_stream(&request);

    request_stream << "POST " << page << " HTTP/1.0\r\n";

    request_stream << "Host: " << host << ":" << port << "\r\n";

    request_stream << "Accept: */*\r\n";

    request_stream << "Content-Length: " << data.length() << "\r\n";

    request_stream << "Content-Type: text/html\r\n";

    request_stream << "Connection: close\r\n\r\n";

    request_stream << data;

    // Send the request.

    boost::asio::write(socket, request);

    // Read the response status line. The response streambuf will automatically

    // grow to accommodate the entire line. The growth may be limited by passing

    // a maximum size to the streambuf constructor.

    boost::asio::streambuf response;

    boost::asio::read_until(socket, response, "\r\n");

    // Check that response is OK.

    std::istream response_stream(&response);

    std::string http_version;

    response_stream >> http_version;

    unsigned int status_code;

    response_stream >> status_code;

    std::string status_message;

    std::getline(response_stream, status_message);

    if (!response_stream || http_version.substr(, ) != "HTTP/")

    {

      reponse_data = "Invalid response";

      return -;

    }

    // 如果服务器返回非200都认为有错,不支持301/302等跳转

    if (status_code != )

    {

      reponse_data = "Response returned with status code != 200 " ;

      return status_code;

    }

    // 传说中的包头可以读下来了

    std::string header;

    std::vector<string> headers;

    while (std::getline(response_stream, header) && header != "\r")

      headers.push_back(header);

    // 读取所有剩下的数据作为包体

    boost::system::error_code error;

    while (boost::asio::read(socket, response,

        boost::asio::transfer_at_least(), error))

    {

    }

    //响应有数据

    if (response.size())

    {

      std::istream response_stream(&response);

      std::istreambuf_iterator<char> eos;

      reponse_data = string(std::istreambuf_iterator<char>(response_stream), eos);

    }

    if (error != boost::asio::error::eof)

    {

      reponse_data = error.message();

      return -;

    }

  }

  catch(std::exception& e)

  {

    reponse_data = e.what();

      return -;

  }

  return ;

}

/*

int main(int argc, char* argv[])

{

  string host = "127.0.0.1";

  string port = "80";

  string page = "/auth/login";

  string data = "user_name=linbc&password=a";

  string reponse_data;

  int ret = post(host, port, page, data, reponse_data);

  if (ret != 0)

    std::cout << "error_code:" << ret << std::endl;

  std::cout << reponse_data << std::endl;

  return 0;

}*/