asio/example/cpp11/iostreams/http_client.cpp
2019-02-17 19:59:39 -10:00

92 lines
2.5 KiB
C++

//
// http_client.cpp
// ~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio/ip/tcp.hpp>
using boost::asio::ip::tcp;
int main(int argc, char* argv[])
{
try
{
if (argc != 3)
{
std::cout << "Usage: http_client <server> <path>\n";
std::cout << "Example:\n";
std::cout << " http_client www.boost.org /LICENSE_1_0.txt\n";
return 1;
}
boost::asio::ip::tcp::iostream s;
// The entire sequence of I/O operations must complete within 60 seconds.
// If an expiry occurs, the socket is automatically closed and the stream
// becomes bad.
s.expires_after(std::chrono::seconds(60));
// Establish a connection to the server.
s.connect(argv[1], "http");
if (!s)
{
std::cout << "Unable to connect: " << s.error().message() << "\n";
return 1;
}
// Send 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.
s << "GET " << argv[2] << " HTTP/1.0\r\n";
s << "Host: " << argv[1] << "\r\n";
s << "Accept: */*\r\n";
s << "Connection: close\r\n\r\n";
// By default, the stream is tied with itself. This means that the stream
// automatically flush the buffered output before attempting a read. It is
// not necessary not explicitly flush the stream at this point.
// Check that response is OK.
std::string http_version;
s >> http_version;
unsigned int status_code;
s >> status_code;
std::string status_message;
std::getline(s, status_message);
if (!s || http_version.substr(0, 5) != "HTTP/")
{
std::cout << "Invalid response\n";
return 1;
}
if (status_code != 200)
{
std::cout << "Response returned with status code " << status_code << "\n";
return 1;
}
// Process the response headers, which are terminated by a blank line.
std::string header;
while (std::getline(s, header) && header != "\r")
std::cout << header << "\n";
std::cout << "\n";
// Write the remaining data to output.
std::cout << s.rdbuf();
}
catch (std::exception& e)
{
std::cout << "Exception: " << e.what() << "\n";
}
return 0;
}