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[/
/ Copyright (c) 2003-2020 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)
/]
[section:iostreams Socket Iostreams]
Boost.Asio includes classes that implement iostreams on top of sockets. These hide
away the complexities associated with endpoint resolution, protocol
independence, etc. To create a connection one might simply write:
ip::tcp::iostream stream("www.boost.org", "http");
if (!stream)
{
// Can't connect.
}
The iostream class can also be used in conjunction with an acceptor to create
simple servers. For example:
io_context ioc;
ip::tcp::endpoint endpoint(tcp::v4(), 80);
ip::tcp::acceptor acceptor(ios, endpoint);
for (;;)
{
ip::tcp::iostream stream;
acceptor.accept(stream.socket());
...
}
Timeouts may be set by calling `expires_at()` or `expires_from_now()` to
establish a deadline. Any socket operations that occur past the deadline will
put the iostream into a "bad" state.
For example, a simple client program like this:
ip::tcp::iostream stream;
stream.expires_from_now(boost::posix_time::seconds(60));
stream.connect("www.boost.org", "http");
stream << "GET /LICENSE_1_0.txt HTTP/1.0\r\n";
stream << "Host: www.boost.org\r\n";
stream << "Accept: */*\r\n";
stream << "Connection: close\r\n\r\n";
stream.flush();
std::cout << stream.rdbuf();
will fail if all the socket operations combined take longer than 60 seconds.
If an error does occur, the iostream's `error()` member function may be used to
retrieve the error code from the most recent system call:
if (!stream)
{
std::cout << "Error: " << stream.error().message() << "\n";
}
[heading See Also]
[link boost_asio.reference.ip__tcp.iostream ip::tcp::iostream],
[link boost_asio.reference.basic_socket_iostream basic_socket_iostream],
[link boost_asio.examples.cpp03_examples.iostreams iostreams examples].
[heading Notes]
These iostream templates only support `char`, not `wchar_t`, and do not perform
any code conversion.
[endsect]
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