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- //
- // posix_chat_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 <cstdlib>
- #include <cstring>
- #include <iostream>
- #include <boost/array.hpp>
- #include <boost/bind.hpp>
- #include <boost/asio.hpp>
- #include "chat_message.hpp"
- #if defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
- using boost::asio::ip::tcp;
- namespace posix = boost::asio::posix;
- class posix_chat_client
- {
- public:
- posix_chat_client(boost::asio::io_context& io_context,
- const tcp::resolver::results_type& endpoints)
- : socket_(io_context),
- input_(io_context, ::dup(STDIN_FILENO)),
- output_(io_context, ::dup(STDOUT_FILENO)),
- input_buffer_(chat_message::max_body_length)
- {
- boost::asio::async_connect(socket_, endpoints,
- boost::bind(&posix_chat_client::handle_connect, this,
- boost::asio::placeholders::error));
- }
- private:
- void handle_connect(const boost::system::error_code& error)
- {
- if (!error)
- {
- // Read the fixed-length header of the next message from the server.
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length),
- boost::bind(&posix_chat_client::handle_read_header, this,
- boost::asio::placeholders::error));
- // Read a line of input entered by the user.
- boost::asio::async_read_until(input_, input_buffer_, '\n',
- boost::bind(&posix_chat_client::handle_read_input, this,
- boost::asio::placeholders::error,
- boost::asio::placeholders::bytes_transferred));
- }
- }
- void handle_read_header(const boost::system::error_code& error)
- {
- if (!error && read_msg_.decode_header())
- {
- // Read the variable-length body of the message from the server.
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.body(), read_msg_.body_length()),
- boost::bind(&posix_chat_client::handle_read_body, this,
- boost::asio::placeholders::error));
- }
- else
- {
- close();
- }
- }
- void handle_read_body(const boost::system::error_code& error)
- {
- if (!error)
- {
- // Write out the message we just received, terminated by a newline.
- static char eol[] = { '\n' };
- boost::array<boost::asio::const_buffer, 2> buffers = {{
- boost::asio::buffer(read_msg_.body(), read_msg_.body_length()),
- boost::asio::buffer(eol) }};
- boost::asio::async_write(output_, buffers,
- boost::bind(&posix_chat_client::handle_write_output, this,
- boost::asio::placeholders::error));
- }
- else
- {
- close();
- }
- }
- void handle_write_output(const boost::system::error_code& error)
- {
- if (!error)
- {
- // Read the fixed-length header of the next message from the server.
- boost::asio::async_read(socket_,
- boost::asio::buffer(read_msg_.data(), chat_message::header_length),
- boost::bind(&posix_chat_client::handle_read_header, this,
- boost::asio::placeholders::error));
- }
- else
- {
- close();
- }
- }
- void handle_read_input(const boost::system::error_code& error,
- std::size_t length)
- {
- if (!error)
- {
- // Write the message (minus the newline) to the server.
- write_msg_.body_length(length - 1);
- input_buffer_.sgetn(write_msg_.body(), length - 1);
- input_buffer_.consume(1); // Remove newline from input.
- write_msg_.encode_header();
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msg_.data(), write_msg_.length()),
- boost::bind(&posix_chat_client::handle_write, this,
- boost::asio::placeholders::error));
- }
- else if (error == boost::asio::error::not_found)
- {
- // Didn't get a newline. Send whatever we have.
- write_msg_.body_length(input_buffer_.size());
- input_buffer_.sgetn(write_msg_.body(), input_buffer_.size());
- write_msg_.encode_header();
- boost::asio::async_write(socket_,
- boost::asio::buffer(write_msg_.data(), write_msg_.length()),
- boost::bind(&posix_chat_client::handle_write, this,
- boost::asio::placeholders::error));
- }
- else
- {
- close();
- }
- }
- void handle_write(const boost::system::error_code& error)
- {
- if (!error)
- {
- // Read a line of input entered by the user.
- boost::asio::async_read_until(input_, input_buffer_, '\n',
- boost::bind(&posix_chat_client::handle_read_input, this,
- boost::asio::placeholders::error,
- boost::asio::placeholders::bytes_transferred));
- }
- else
- {
- close();
- }
- }
- void close()
- {
- // Cancel all outstanding asynchronous operations.
- socket_.close();
- input_.close();
- output_.close();
- }
- private:
- tcp::socket socket_;
- posix::stream_descriptor input_;
- posix::stream_descriptor output_;
- chat_message read_msg_;
- chat_message write_msg_;
- boost::asio::streambuf input_buffer_;
- };
- int main(int argc, char* argv[])
- {
- try
- {
- if (argc != 3)
- {
- std::cerr << "Usage: posix_chat_client <host> <port>\n";
- return 1;
- }
- boost::asio::io_context io_context;
- tcp::resolver resolver(io_context);
- tcp::resolver::results_type endpoints = resolver.resolve(argv[1], argv[2]);
- posix_chat_client c(io_context, endpoints);
- io_context.run();
- }
- catch (std::exception& e)
- {
- std::cerr << "Exception: " << e.what() << "\n";
- }
- return 0;
- }
- #else // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
- int main() {}
- #endif // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR)
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