Cross-platform C++/boost/asio simple HTTP POST request client model

As an echo, write a C + + version of the synchronous HTTP Post client feature, if you need a pure C version, step here

Linux Pure C Simple HTTP POST request client model

Explain the basic HTTP POST protocol

• Implementation of TCP message boundaries through \ r \ n
• The first paragraph of each request POST/A.B http/1.1
  • The method of POST HTTP, and the most commonly used get, of course there are several other, skipped
  • /A.B requested page path, for example, if it is the homepage, the most common is/
  • http/1.1 HTTP protocol version number, legend has been out of 2, there are magic Google out to replace the HTTP protocol spdy
• This information indicates that this is a form
  • content-type:application/x-www-form-urlencoded
• This information indicates the length of the package of the HttpPost, not required
• Content-length:12
• And then there's a blank line, which represents the next package.

Just a request, it's easier to talk about the response.

• Response Content http/1.1 OK
  • 200 is the status in the transmission, 404 didn't find it, wait!
  • http/1.1 indicates the version number of the HTTP
  • Of course, if Baotou can also exist, it is not introduced here
  • Then there is a blank line, split is the package body

All right, just go to the code.

#include <iostream>#include<istream>#include<ostream>#include<string>#include<boost/asio.hpp>usingboost::asio::ip::tcp;usingSTD::string;intPostConst string& Host,Const string& Port,Const string& Page,Const string& Data,string&reponse_data) {  Try{Boost::asio::io_service io_service; //if the Io_service exists for reuse    if(io_service.stopped ()) Io_service.reset (); //get all IPs under the domain name from DNStcp::resolver Resolver (io_service);    Tcp::resolver::query Query (host, port); Tcp::resolver::iterator Endpoint_iterator=resolver.resolve (query); //attempt to connect to one of these IPs until successfultcp::socket socket (io_service);     Boost::asio::connect (socket, endpoint_iterator); //Form the request. We Specify the "Connection:close" header so, the//server would close the socket after transmitting the response. this would//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 would automatically//grow to accommodate the entire line. The growth is 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::stringhttp_version; Response_stream>>http_version; unsignedintStatus_code; Response_stream>>Status_code; STD::stringStatus_message;    Std::getline (Response_stream, status_message); if(!response_stream | | http_version.substr (0,5) !="http/") {Reponse_data="Invalid Response"; return-2; }    //If the server returns a non-200 is considered to be wrong, does not support 301/302 and other jumps    if(Status_code! = $) {Reponse_data="Response returned with status code! =" ; returnStatus_code; }    //The legendary Baotou can be read down.STD::stringheader; Std::vector<string>headers;  while(Std::getline (Response_stream, header) && header! ="\ r") Headers.push_back (header); //Read all the rest of the data as the package bodyBoost::system::error_code error;  while(Boost::asio::read (socket, response, Boost::asio::transfer_at_least (1, error)) {}//Response with Data    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-3; }  }  Catch(std::exception&e) {reponse_data=E.what (); return-4; }  return 0;}intMainintargcChar*argv[]) {  stringHost ="127.0.0.1"; stringPort =" the"; stringpage ="/auth/login"; stringdata ="user_name=linbc&password=a"; stringReponse_data; intRET =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;}

Compile it.

g++ Post.cc-std=c++11-pthread-lboost_system

Cross-platform C++/boost/asio simple HTTP POST request client model