使用 boost 检查端口可用性答案

【问题标题】：Check port availability with boost使用 boost 检查端口可用性
【发布时间】：2016-03-15 01:07:12
【问题描述】：

我正在尝试检查我电脑上的端口是否可用。但是这段代码在 acceptor.listen(); 之后会崩溃。崩溃堆栈跟踪停止于：

 detail/impl/win_iocp_socket_service_base.ipp

我的代码是：

    try {
        boost::asio::io_service io_service;
        boost::asio::ip::tcp::acceptor acceptor(io_service);
        boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::address::from_string("127.0.0.1"), port);
        acceptor.open(endpoint.protocol());
        acceptor.set_option(boost::asio::ip::tcp::acceptor::reuse_address(false));
        acceptor.bind(endpoint);
        acceptor.listen();
    }
    catch (...) {
        // port busy
    }

如何使用 boost 来检查这一点，或者我的代码中的问题在哪里？

UPD1：我尝试了 here 的以下代码：

bool port_in_use(unsigned short port) {
using namespace boost::asio;
using ip::tcp;

    io_service svc;
    tcp::acceptor a(svc);

    boost::system::error_code ec;
    a.open(tcp::v4(), ec) || a.bind({ tcp::v4(), port }, ec);

    return ec == error::address_in_use;
}

但函数执行后，我的程序仍然在原地崩溃。

【问题讨论】：

这有帮助吗stackoverflow.com/questions/33358321/…
不，退出函数时崩溃仍然存在
这是什么意思，@user2123079？你尝试了什么？什么功能？
看来这个功能是不相关的。（怎么可能是“在同一个地方”呢？那个更新中不存在“同一个地方”。）在其他地方寻找 UB 的案例。使其成为 SSCCE。另见 Nobody Writes Testcases Anymore 和 Solve your problem by almost asking a question on Stackoverflow

标签： c++ boost boost-asio

【解决方案1】：

好吧，我找到了如何在 Windows 中执行此操作（来自 link）：

#ifndef UNICODE
#define UNICODE
#endif

#define WIN32_LEAN_AND_MEAN

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>

// Need to link with Ws2_32.lib
#pragma comment(lib, "ws2_32.lib")

int wmain()
{
    //----------------------
    // Initialize Winsock
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != NO_ERROR) {
        wprintf(L"WSAStartup function failed with error: %d\n", iResult);
        return 1;
    }
    //----------------------
    // Create a SOCKET for connecting to server
    SOCKET ConnectSocket;
    ConnectSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (ConnectSocket == INVALID_SOCKET) {
        wprintf(L"socket function failed with error: %ld\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }
    //----------------------
    // The sockaddr_in structure specifies the address family,
    // IP address, and port of the server to be connected to.
    sockaddr_in clientService;
    clientService.sin_family = AF_INET;
    clientService.sin_addr.s_addr = inet_addr("127.0.0.1");
    clientService.sin_port = htons(27015);

    //----------------------
    // Connect to server.
    iResult = connect(ConnectSocket, (SOCKADDR *) & clientService, sizeof (clientService));
    if (iResult == SOCKET_ERROR) {
        wprintf(L"connect function failed with error: %ld\n", WSAGetLastError());
        iResult = closesocket(ConnectSocket);
        if (iResult == SOCKET_ERROR)
            wprintf(L"closesocket function failed with error: %ld\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    wprintf(L"Connected to server.\n");

    iResult = closesocket(ConnectSocket);
    if (iResult == SOCKET_ERROR) {
        wprintf(L"closesocket function failed with error: %ld\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    WSACleanup();
    return 0;
}

【讨论】：