Socket 连接简易编程

客户端:

#include <iostream>
#include <winsock2.h>

using namespace std;

#pragma  comment (lib, "ws2_32.lib")

#define PORT 4000
#define IP_ADDRESS "127.0.0.1"

int main(int agrc, char * agrv[])
{
    WSADATA ws;
    SOCKET ClientSocket;
    struct sockaddr_in ServerAddr;
    int Ret = 0;
    int AddrLen = 0;
    HANDLE hTread = NULL;
    char SendBuffer[MAX_PATH];

    int errorcode = 0;

    //Init Window Socket
    if ((errorcode = WSAStartup(MAKEWORD(2, 2), &ws)) != 0)
    {
        cout << "Init Windows Socket Failed::" << errorcode << endl;
        return -1;
    }

    // Create Socket 
    ClientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (ClientSocket == INVALID_SOCKET)
    {
        cout << "Create Socket Failed::" << WSAGetLastError() << endl;
        return -1;
    }
    ServerAddr.sin_family = AF_INET;
    ServerAddr.sin_addr.s_addr = inet_addr(IP_ADDRESS);
    ServerAddr.sin_port = htons(PORT);
    memset(ServerAddr.sin_zero, 0x00, 8);

    // connect
    Ret = connect(ClientSocket, (struct sockaddr*)&ServerAddr, sizeof(ServerAddr));
    if (Ret == SOCKET_ERROR)
    {
        cout << "Connect Error::" << WSAGetLastError() << endl;
        return -1;
    }else{
        cout << "连接成功!!" << endl;
    }

    while (true)
    {
        cin.getline(SendBuffer, sizeof(SendBuffer));
        Ret = send(ClientSocket, SendBuffer, (int)strlen(SendBuffer), 0);
        if (Ret == SOCKET_ERROR)
        {
            cout << "Sentd Info Error::" << GetLastError() << endl;
            break;
        }
    }

    closesocket(ClientSocket);
    WSACleanup();
    return 0;
}

服务端:

#include <iostream>
#include <WinSock2.h>

using namespace std;

#pragma comment (lib, "ws2_32.lib")

#define PORT 4000
#define IP_ADDREESS "127.0.0.1"

int main(int agrc, char* argc[])
{
    WSADATA ws;  // 之后储存WSAStartUP返回 的数据， 全称：Windows Socker API Data
    SOCKET ServerSocket = 0, ClientSocket = 0;
    struct sockaddr_in LocalAddr, ClientAddr;
    int errorcode;
    int Ret = 0;
    int AddrLen = 0;
    HANDLE hThread = NULL;


    //Init Windwos Socket
    if ((errorcode = WSAStartup(MAKEWORD(2, 2), &ws)) != 0)
    {
        cout << "Create Socket Failed:" << errorcode << endl;
        return -1;
    }

    // CreateSocket 
    ServerSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (ServerSocket == INVALID_SOCKET)
    {
        cout << "Create Socket Failed::" << WSAGetLastError() << endl;
        return -1;
    }

    LocalAddr.sin_family = AF_INET;
    LocalAddr.sin_addr.s_addr = inet_addr(IP_ADDREESS);  //将ip 127.0.0.1 转换成网络字节序 
    LocalAddr.sin_port = htons(PORT);       // 转换为网络字节序
    memset(LocalAddr.sin_zero, 0x00, 8);

    //Bind Socket
    Ret = bind(ServerSocket,(struct sockaddr*)&LocalAddr, sizeof(LocalAddr));
    if (Ret != 0)
    {
        cout << "Bind Socket Failded::" << WSAGetLastError() << endl;
        return -1;
    }

    // listen
    Ret = listen(ServerSocket, 10);
    if(Ret != 0)
    {
        cout << "Listen Socket Failed::" << WSAGetLastError() << endl;
        return -1;
    }

    cout << " 服务端已经启动!" << endl;

    while (true)
    {
        AddrLen = sizeof(ClientAddr);
        ClientSocket = accept(ServerSocket, (struct sockaddr*)&ClientAddr, &AddrLen);

        if (ClientSocket == INVALID_SOCKET)
        {
            cout << "Accept Failed::" << WSAGetLastError() << endl;
            break;
        }

        char RecvBuffer[MAX_PATH];
        while (true)
        {
            memset(RecvBuffer, 0x00, sizeof(RecvBuffer));
            // 接收数据
            // recv函数返回实际copy的字节数；
            //  copy时出错，返回SOCKET_ERROR;等待协议接收数据时网络中断，返回0。
            Ret = recv(ClientSocket, RecvBuffer, MAX_PATH, 0);
            if (Ret == 0 || Ret == SOCKET_ERROR)
            {

                cout << "Recv Failed::" << WSAGetLastError() << endl;
                break;
            }
            cout << "接收到的客户信息为:" << RecvBuffer << endl;
        }

    }
    closesocket(ServerSocket);
    closesocket(ClientSocket);
    WSACleanup();
    return 0;
}

---

AF_INET 与 AF_INET6
AF_INET（又称 PF_INET）是 IPv4 网络协议的套接字类型，AF_INET6 则是 IPv6 的；而 AF_UNIX 则是 Unix 系统本地通信。

选择 AF_INET 的目的就是使用 IPv4 进行通信。因为 IPv4 使用 32 位地址，相比 IPv6 的 128 位来说，计算更快，便于用于局域网通信。

而且 AF_INET 相比 AF_UNIX 更具通用性，因为 Windows 上有 AF_INET 而没有 AF_UN