Boost.Asio应用程序在创建接收器对象时引发异常

Question

I am doing a tutorial from www.highscore.de regarding Boost.Asio. This is the example I am trying to run:

#include <boost/asio.hpp>
#include <string>

boost::asio::io_service io_service;
boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), 80);
boost::asio::ip::tcp::acceptor acceptor(io_service, endpoint);
boost::asio::ip::tcp::socket sock(io_service);
std::string data = "HTTP/1.1 200 OK\r\nContent-Length: 13\r\n\r\nHello, world!";

void write_handler(const boost::system::error_code &ec, std::size_t bytes_transferred)
{
}

void accept_handler(const boost::system::error_code &ec)
{
    if (!ec)
    {
        boost::asio::async_write(sock, boost::asio::buffer(data), write_handler);
    }
}

int main()
{
    acceptor.listen();
    acceptor.async_accept(sock, accept_handler);
    io_service.run();
} 

But everytime it throws on exception on this line:

boost::asio::ip::tcp::acceptor acceptor(io_service, endpoint);

Looking at the stack trace, this line inside basic_socket_acceptor throws:

boost::asio::detail::throw_error(ec, "bind");

Does anyone has an idea why ?

Answer 1

If you can catch the exception, you'll probably get more information by calling the what() method. You'll find this easier if you move all of those global variables into a function and run from there. That way, you can catch the exception more easily.

That said, on most systems you're not allowed to bind to port 80 as a non-privileged user. Try something else, and see if you have more luck.