// // sync_client.cpp // ~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2016 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 #include #include #include #include using asio::ip::tcp; int main(int argc, char* argv[]) { try { if (argc != 3) { std::cout << "Usage: sync_client \n"; std::cout << "Example:\n"; std::cout << " sync_client www.boost.org /LICENSE_1_0.txt\n"; return 1; } asio::io_context io_context; // Get a list of endpoints corresponding to the server name. tcp::resolver resolver(io_context); tcp::resolver::results_type endpoints = resolver.resolve(argv[1], "http"); // Try each endpoint until we successfully establish a connection. tcp::socket socket(io_context); asio::connect(socket, endpoints); // 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. asio::streambuf request; std::ostream request_stream(&request); request_stream << "GET " << argv[2] << " HTTP/1.0\r\n"; request_stream << "Host: " << argv[1] << "\r\n"; request_stream << "Accept: */*\r\n"; request_stream << "Connection: close\r\n\r\n"; // Send the request. 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. asio::streambuf response; 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(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; } // Read the response headers, which are terminated by a blank line. asio::read_until(socket, response, "\r\n\r\n"); // Process the response headers. std::string header; while (std::getline(response_stream, header) && header != "\r") std::cout << header << "\n"; std::cout << "\n"; // Write whatever content we already have to output. if (response.size() > 0) std::cout << &response; // Read until EOF, writing data to output as we go. asio::error_code error; while (asio::read(socket, response, asio::transfer_at_least(1), error)) std::cout << &response; if (error != asio::error::eof) throw asio::system_error(error); } catch (std::exception& e) { std::cout << "Exception: " << e.what() << "\n"; } return 0; }