TCP通信，tcp

TCP通信，tcp

//網絡套接字編程實例，服務器端，TCP通信。
#include <WinSock2.h>
#pragma comment(lib,"ws2_32.lib")
#include <iostream>
#include <windows.h>
using namespace std;

int main()
{
    WSADATA wsaData;
    WSAStartup(MAKEWORD(2,2),&wsaData);  //初始化版本
    SOCKET sList = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  //初始化socket
    if (sList == INVALID_SOCKET) //判斷socket是否建立成功
    {
        cout << "socket error\n";
    }
    else
    {
        cout << "socket success\n";
    }
    sockaddr_in asd;   //申明bind中addr參數，這是申明，一個結構體。
    asd.sin_family = AF_INET;        //設置結構體，必須是：AF_INET
    asd.sin_port = htons(1990);      //指定TCP或UDP通信服務端口號，htons函數將主機無符號短整型轉換成網絡字節順序，1990是本地監聽的端口號。
    asd.sin_addr.S_un.S_addr = INADDR_ANY; //INADDR_ANY表示所有可用地址
    if (bind(sList, (LPSOCKADDR)&asd, sizeof(asd)) == SOCKET_ERROR) //綁定本地IP和端口
    {
        cout << "bind error";
        closesocket(sList);
        return 0;
    }
    if (listen(sList, 5) == SOCKET_ERROR)
    {
        cout << "listen error";
        closesocket(sList);
        return 0;
    }//監聽,5為連接最數,注意listen只支持上面的SOCK_STREAM也就是TCP，UDP不用條用此函數。

    // 循環接受客戶的連接請求
    sockaddr_in remoteAddr;
    SOCKET sClient;
    int nAddrlen = sizeof(remoteAddr);
    char revData[255];
    while (1)
    {
        // 接受一個新連接
        sClient = accept(sList, (SOCKADDR*)&remoteAddr, &nAddrlen);
        //錯誤
        if (sClient == INVALID_SOCKET)
        {
            cout << "accept error";
            continue;
        }
        //打印出連接者的ip
        cout << " 接受到一個連接：" << inet_ntoa(remoteAddr.sin_addr)<<"\n";
        int ret = recv(sClient, revData, 255, 0);
        if (ret > 0)
        {
            //為了防止打印出錯，把字符串結尾設成0x00
            revData[ret] = 0x00;
            cout<<revData;
        }
        //發送給客戶端數據
        char *buff = "握手，我是來自服務端的信息，TCP建立成功\n";
        send(sClient, buff, strlen(buff), 0);
        closesocket(sClient);
    }
    closesocket(sList);
    system("pause");
    return 0;
}

//網絡套接字編程實例，客戶端。
#include <WinSock2.h>
#pragma comment(lib,"ws2_32.lib")
#include <iostream>
#include <windows.h>
#include <WS2tcpip.h>
using namespace std;

int main()
{
    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);  //初始化版本
    SOCKET sList = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  //初始化socket
    if (sList == INVALID_SOCKET) //判斷socket是否建立成功
    {
        cout << "socket error\n";
    }
    else
    {
        cout << "socket success\n";
    }
    sockaddr_in asd;   //申明bind中addr參數，這是申明，一個結構體。
    asd.sin_family = AF_INET;        //設置結構體，必須是：AF_INET
    asd.sin_port = htons(1990);      //指定TCP或UDP通信服務端口號，htons函數將主機無符號短整型轉換成網絡字節順序，1990是本地監聽的端口號。
    asd.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); //INADDR_ANY表示所有可用地址
    if (connect(sList, (sockaddr*)&asd, sizeof(asd)) == SOCKET_ERROR)
    {
        cout<<"connect error\n";
        closesocket(sList);
        return 0;
    }
    char *buff = "我是來自客戶端的信息";
    int nAddrlen = sizeof(asd);
    char revData[255];
    send(sList, buff, strlen(buff), 0);
    int ret = recv(sList, revData, 255, 0);
    if (ret > 0)
    {
        revData[ret] = 0x00;
        cout << revData;
    }
    closesocket(sList);
    WSACleanup();
    system("pause");
    return 0;
}