使用TCP

1.基本流程:

　　服务端: 创建socket->bind()地址和端口->listen()设置为监听模式->accept()接受客户端请求,收到了就返回新socket,这个

　　　　socket包含了客户端的信息->recv()接受数据,send()发送数据->shutdown()通知对方不再发送或接受数据.然后closesocket()关闭客户端套接字

　　　　->继续监听或者closesocket()关闭本地socket.

　　客户端:socket()创建本地socket,connect()将本地socket连接到服务器->send()发送,recv()接受数据->完了后shutdown()通知对方不再继续通信,

closesocket()关闭socket.

简单实例:

服务端:

#include <WinSock2.h>
#include<stdio.h>
#include<windows.h>
#include<string.h>
#pragma  comment(lib,"ws2_32.lib")

void main()
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData))
    {
        printf("版本错误
");
        return;
    }
    int status;
    int len=sizeof(SOCKADDR);
    char recvBuffer[1024];
    char sendBuffer[1024];
    SOCKET server_socket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
    SOCKET client_socket;
    SOCKADDR_IN bind_addr;
    SOCKADDR_IN client_addr;

    bind_addr.sin_family = AF_INET;
    bind_addr.sin_port = htons(8888);
    bind_addr.sin_addr.S_un.S_addr = htonl(ADDR_ANY);
    status = bind(server_socket, (const sockaddr*)&bind_addr, sizeof(sockaddr));
    if (status==SOCKET_ERROR)
    {
        printf("bind error code is %d
", WSAGetLastError());
        WSACleanup();
        return;
    }
    status = listen(server_socket, 1);
    if (status== SOCKET_ERROR)
    {
        printf("listen error code is %d
", WSAGetLastError());
        WSACleanup();
        return;
    }
    client_socket = accept(server_socket, (sockaddr*)&client_addr, &len);
    if (client_socket == INVALID_SOCKET)
    {
        printf("accept error code is %d
", WSAGetLastError());
        closesocket(server_socket);
        WSACleanup();
        
        return;
    }
    printf("info: connected by %s %d
", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
    printf("info: type quit to quit
");
    while (1)
    {
        memset(recvBuffer, 0, sizeof(recvBuffer));
        memset(sendBuffer, 0, sizeof(sendBuffer));
        recv(client_socket, recvBuffer, sizeof(recvBuffer), 0);
        if (strcmp(recvBuffer, "quit")==0)
        {
            printf("客户端关闭连接,服务端将关闭
");
            closesocket(server_socket);
            closesocket(client_socket);
            WSACleanup();
            return;
        }
        printf("收到:%s
", recvBuffer);
        printf("输入要发送的内容
");
        scanf("%s", sendBuffer);
        if (strcmp(sendBuffer, "quit") == 0)
        {
            printf("退出!
");
            send(server_socket, "quit", 5, 0);
            closesocket(server_socket);
            closesocket(client_socket);
            WSACleanup();
            return;
        }
        send(client_socket, sendBuffer, sizeof(sendBuffer), 0);
    }

}

 客户端:

#include <WinSock2.h>
#include<stdio.h>
#include<windows.h>
#include<string.h>
#pragma  comment(lib,"ws2_32.lib")


void main()
{
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData))
    {
        printf("版本错误
");
        return;
    }

    int len = 0;
    int status;
    char recvBuffer[1024];
    char sendBuffer[1024];
    SOCKET server_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    SOCKADDR_IN addr;
    addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    addr.sin_port = htons(8888);
    addr.sin_family = AF_INET;

    status = connect(server_socket, (sockaddr*)&addr, sizeof(sockaddr));
    if (status==SOCKET_ERROR)
    {
        printf("连接失败,错误码:%d
", WSAGetLastError());
        closesocket(server_socket);
        WSACleanup();
    }
    printf("info: 连接成功
");
    printf("发送quit退出
");
    while (1)
    {
        memset(recvBuffer, 0, sizeof(recvBuffer));
        memset(sendBuffer, 0, sizeof(sendBuffer));
        printf("输入发送的消息
");
        scanf("%s", sendBuffer);
        if (strcmp(sendBuffer, "quit")==0)
        {
            printf("退出!
");
            send(server_socket, "quit", 5, 0);
            closesocket(server_socket);
            WSACleanup();
            return;
        }
        send(server_socket, sendBuffer, sizeof(sendBuffer), 0);
        recv(server_socket, recvBuffer, sizeof(recvBuffer), 0);
        if (strcmp(recvBuffer, "quit") == 0)
        {
            printf("服务端关闭连接,客户端将关闭
");
            closesocket(server_socket);
            WSACleanup();
            return;
        }
        printf("接收到: %s
", recvBuffer);
    }
}