Function main

example/cpp11/iostreams/http_client.cpp:19–91

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.