1 //
2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // Official repository: https://github.com/boostorg/beast
8 //
9
10 //------------------------------------------------------------------------------
11 //
12 // Example: HTTP client, synchronous
13 //
14 //------------------------------------------------------------------------------
15
16 //[example_http_client
17
18 #include <boost/beast/core.hpp>
19 #include <boost/beast/http.hpp>
20 #include <boost/beast/version.hpp>
21 #include <boost/asio/connect.hpp>
22 #include <boost/asio/ip/tcp.hpp>
23 #include <cstdlib>
24 #include <iostream>
25 #include <string>
26
27 namespace beast = boost::beast; // from <boost/beast.hpp>
28 namespace http = beast::http; // from <boost/beast/http.hpp>
29 namespace net = boost::asio; // from <boost/asio.hpp>
30 using tcp = net::ip::tcp; // from <boost/asio/ip/tcp.hpp>
31
32 // Performs an HTTP GET and prints the response
main(int argc,char ** argv)33 int main(int argc, char** argv)
34 {
35 try
36 {
37 // Check command line arguments.
38 if(argc != 4 && argc != 5)
39 {
40 std::cerr <<
41 "Usage: http-client-sync <host> <port> <target> [<HTTP version: 1.0 or 1.1(default)>]\n" <<
42 "Example:\n" <<
43 " http-client-sync www.example.com 80 /\n" <<
44 " http-client-sync www.example.com 80 / 1.0\n";
45 return EXIT_FAILURE;
46 }
47 auto const host = argv[1];
48 auto const port = argv[2];
49 auto const target = argv[3];
50 int version = argc == 5 && !std::strcmp("1.0", argv[4]) ? 10 : 11;
51
52 // The io_context is required for all I/O
53 net::io_context ioc;
54
55 // These objects perform our I/O
56 tcp::resolver resolver(ioc);
57 beast::tcp_stream stream(ioc);
58
59 // Look up the domain name
60 auto const results = resolver.resolve(host, port);
61
62 // Make the connection on the IP address we get from a lookup
63 stream.connect(results);
64
65 // Set up an HTTP GET request message
66 http::request<http::string_body> req{http::verb::get, target, version};
67 req.set(http::field::host, host);
68 req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);
69
70 // Send the HTTP request to the remote host
71 http::write(stream, req);
72
73 // This buffer is used for reading and must be persisted
74 beast::flat_buffer buffer;
75
76 // Declare a container to hold the response
77 http::response<http::dynamic_body> res;
78
79 // Receive the HTTP response
80 http::read(stream, buffer, res);
81
82 // Write the message to standard out
83 std::cout << res << std::endl;
84
85 // Gracefully close the socket
86 beast::error_code ec;
87 stream.socket().shutdown(tcp::socket::shutdown_both, ec);
88
89 // not_connected happens sometimes
90 // so don't bother reporting it.
91 //
92 if(ec && ec != beast::errc::not_connected)
93 throw beast::system_error{ec};
94
95 // If we get here then the connection is closed gracefully
96 }
97 catch(std::exception const& e)
98 {
99 std::cerr << "Error: " << e.what() << std::endl;
100 return EXIT_FAILURE;
101 }
102 return EXIT_SUCCESS;
103 }
104
105 //]
106