一個簡單的TCP通信程序Demo

實現一個最簡單的客戶端和服務端的通信程序

服務器程序工作
1.初始化 Winsock庫
2.創建監聽套接字(socket()函數)
3.填寫要綁定的本地地址結構(bind()函數)
4.給監聽套接字綁定本地IP地址
5.開始監聽(listen()函數)
6.循環執行 調用accept()函數接收客戶端連接請求,如果accept()函數返回成功.則調用send()函數向客戶端發送數據或者調用recv()函數從客戶端接收數據

客戶端程序工作
1.初始化 Winsock庫
2.創建通信套接字(socket()函數)
3.填寫要連接的服務器的地址結構
4.與服務器建立連接(connect()函數)
5.調用recv()函數接收服務器數據,send()函數發送數據給服務器

服務器程序代碼:

// Server.cpp : Defines the entry point for the console application.
//

#include <iostream>
#include <WinSock2.h>
using namespace std;

#pragma comment(lib, "WS2_32.lib")
//表示鏈接WS2_32.lib這個庫。
#define  PORT 1024

int main()
{
    SOCKET sock_server, newsock;
    struct sockaddr_in server_addr, client_addr; 
    char msg[] = { "Hello clinet" };
    // 初始化 winsock2.dll[12/27/2017 MagicScaring]
    WSADATA wsaData;
    WORD wVersionRequested = MAKEWORD(2, 2);        //生成版本號
    if (WSAStartup(wVersionRequested, &wsaData) != 0)
    {
        cout << "加載 winsock.dll失敗" << endl;
        return 0;
    }
    // 創建套接字 [12/27/2017 MagicScaring]
    if ((sock_server = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
    {
        cout << "創建套接字失敗! 錯誤代碼:" << WSAGetLastError() << endl;
        WSACleanup();                   //註銷WinSock動態鏈接庫
        return 0;
    }
    // 填寫需要綁定的本地地址 [12/27/2017 MagicScaring]
    int addr_len = sizeof(struct sockaddr_in);
    memset((void*)&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sock_server, (struct sockaddr*)&server_addr, addr_len) != 0)
    {
        cout << "綁定失敗!錯誤代碼:" << WSAGetLastError() << endl;
        closesocket(sock_server);               //關閉已連接套接字
        WSACleanup();                           //註銷WinSock動態鏈接庫
        return 0;
    }

    // 開始監聽 [12/27/2017 MagicScaring]
    if (listen(sock_server, 0) != 0)
    {
        cout << "listen調用失敗!錯誤代碼:" << WSAGetLastError() << endl;
        closesocket(sock_server);
        WSACleanup();
        return 0;
    }
    else
    {
        cout << "listening...." << endl;
    }
    // 循環:接收連接請求並收發數據 [12/27/2017 MagicScaring]
    int size;
    while (true)
    {
        if ((newsock = accept(sock_server, (struct sockaddr *)&client_addr, &addr_len)) == INVALID_SOCKET)
        {
            cout << "accept 函數調用失敗! 錯誤代碼:" << WSAGetLastError() << endl;
            break;
        }
        else
        {
            cout << "成功接收到一個連接請求!" << endl;
            size = send(newsock, msg, sizeof(msg), 0);
            if (size == SOCKET_ERROR)
            {
                cout << "發送信息失敗! 錯誤代碼:" << WSAGetLastError() << endl;
                closesocket(newsock);
                continue;
            }
            else if (size == 0)
            {
                cout << "對方已關閉連接" << endl;
                closesocket(newsock);
                continue;
            }
            else
            {
                cout << "信息發送成功" << endl;
            }
            size = recv(newsock, msg, sizeof(msg), 0);
            if (size == SOCKET_ERROR)
            {
                cout << "接收信息失敗！ 錯誤代碼：" << WSAGetLastError() << endl;
                closesocket(newsock);
                WSACleanup();
                return 0;
            }
            else if (size == 0)
            {
                cout << "對方已關閉連接" << endl;
                closesocket(newsock);
                WSACleanup();
                return 0;
            }
            else
            {
                cout << "The message from Client:" << msg << endl;

            }
        }
    }

    return 0;
}

客戶端程序代碼:

// Client.cpp : Defines the entry point for the console application.
//

#include <iostream>
#include <WinSock2.h>
using namespace std;

#pragma comment(lib, "WS2_32.lib")
//表示鏈接WS2_32.lib這個庫。
#define  PORT 1024

int main()
{
    SOCKET sock_client;
    struct sockaddr_in server_addr;
    int addr_len = sizeof(struct sockaddr_in);
    char msgbuffer[1000];
    memset(msgbuffer, 0, sizeof(msgbuffer));
    // 初始化 winsock2.dll[12/27/2017 MagicScaring]
    WSADATA wsaData;
    WORD wVersionRequested = MAKEWORD(2, 2);        //生成版本號
    if (WSAStartup(wVersionRequested, &wsaData) != 0)
    {
        cout << "加載 winsock.dll失敗" << endl;
        return 0;
    }
    // 創建套接字 [12/27/2017 MagicScaring]
    if ((sock_client = socket(AF_INET, SOCK_STREAM, 0)) == SOCKET_ERROR)
    {
        cout << "創建套接字失敗! 錯誤代碼:" << WSAGetLastError() << endl;
        WSACleanup();                   //註銷WinSock動態鏈接庫
        return 0;
    }
    // 填寫服務器地址 [12/27/2017 MagicScaring]
    char IP[20] = { "192.168.5.38" };
    /*char IP[20];
    cout << "輸入服務器地址:" << endl;
    cin >> IP;*/
    memset((void*)&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = inet_addr(IP);

    // 與服務器建立連接 [12/27/2017 MagicScaring]
    if (connect(sock_client, (struct sockaddr*)&server_addr, addr_len) == SOCKET_ERROR)
    {
        cout << "連接失敗! 錯誤代碼:" << WSAGetLastError() << endl;
        closesocket(sock_client);
        WSACleanup();
        return 0;
    }
    while (true)
    {
        int size;
        if ((size = recv(sock_client, msgbuffer, sizeof(msgbuffer), 0)) == SOCKET_ERROR)
        {
            cout << "接收信息失敗！ 錯誤代碼：" << WSAGetLastError() << endl;
            closesocket(sock_client);
            WSACleanup();
            return 0;
        }
        else if (size == 0)
        {
            cout << "對方已關閉連接" << endl;
            closesocket(sock_client);
            WSACleanup();
            return 0;
        }
        else
        {
            cout << "The message from Server:" << msgbuffer << endl;
        }
        char send_msg[1000] = { "Hello server" };
        if((size = send(sock_client, send_msg, sizeof(send_msg),0)) == SOCKET_ERROR)
        {
            cout << "發送信息失敗! 錯誤代碼:" << WSAGetLastError() << endl;
        }
        else if (size == 0)
        {
            cout << "對方已關閉連接" << endl;
        }
        else
        {
            cout << "信息發送成功" << endl;
        }

    }
    closesocket(sock_client);
    WSACleanup();

    return 0;
}

服務器程序運行結果:

客戶端程序運行結果: