思维导图

练习题

1.实现TCP服务器和客户端之间的通信

server.c

#include <myhead.h>

int main(int argc, char const *argv[])
{
    //创建套接字
    int sfd = socket(AF_INET, SOCK_STREAM, 0);
    //端口复用，作用：关闭服务器后再启动不会等待
    int reuse = 1;
    setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
    //填充IP和端口
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(1234);
    sin.sin_addr.s_addr = inet_addr("192.168.124.51");
    //服务器绑定套接字
    bind(sfd, (struct sockaddr *)&sin, sizeof(sin));
    //监听客户端是否发送请求
    listen(sfd, 128);
    //创建用来传递消息的套接字
    socklen_t socklen = sizeof(sin);
    int newfd = accept(sfd, (struct sockaddr *)&sin, &socklen);
    printf("[%s:%d]发来连接请求\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
    //消息的发送与接收
    char buf[128] = "";
    while (1)
    {
        memset(buf, 0, sizeof(buf));
        //接收消息
        int res=recv(newfd, buf, sizeof(buf), 0);
        if (res == 0)
        {
            printf("客户端下线\n");
            break;
        }
        printf("[%s:%d] %s\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), buf);
        //发送消息
        send(newfd, buf, sizeof(buf), 0);
    }
    //关闭服务器
    close(newfd);
    close(sfd);
    return 0;
}

client.c

#include <myhead.h>

int main(int argc, char const *argv[])
{
    //创建套接字
    int cfd = socket(AF_INET, SOCK_STREAM, 0);
    //填充客户端IP和端口
    struct sockaddr_in cin;
    cin.sin_family = AF_INET;
    cin.sin_port = htons(4321);
    cin.sin_addr.s_addr = inet_addr("192.168.124.51");
    //服务器绑定，也可以不绑定，不绑定客户端端口号随机
    bind(cfd, (struct sockaddr *)&cin, sizeof(cin));
    //服务器IP和端口
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(1234);
    sin.sin_addr.s_addr = inet_addr("192.168.124.51");
    //连接服务器，向服务器发送请求
    connect(cfd, (struct sockaddr *)&sin, sizeof(sin));
    //消息的发送与接收
    char buf[128] = "";
    while (1)
    {
        memset(buf, 0, sizeof(buf));
        //输入消息
        printf("[%s:%d] 请输入--->", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
        fgets(buf, sizeof(buf), stdin);
        buf[strlen(buf) - 1] = '\0';
        //发送消息
        send(cfd, buf, sizeof(buf), 0);
        //接收消息
        recv(cfd, buf, sizeof(buf), 0);
        if (strcmp(buf, "q") == 0)
        {
            printf("下线\n");
            break;
        }
    }
    //关闭客户端    
    close(cfd);
    return 0;
}

2.服务器和客户端通信实现客户端控制服务器端机械臂摆动

#include <myhead.h>
#define SER_IP "192.168.124.19"
#define SER_PORT 8888

int main(int argc, char const *argv[])
{
    //创建套接字
    int cfd = socket(AF_INET, SOCK_STREAM, 0);
    //服务器IP和端口
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(1234);
    sin.sin_addr.s_addr = inet_addr("192.168.124.19");
    //连接服务器，向服务器发送请求
    connect(cfd, (struct sockaddr *)&sin, sizeof(sin));

    //循环操作，判断w蓝色左 a红色左 s蓝色右 d红色右
    char arr[5];
    arr[0] = 0xff;
    arr[4] = 0xff;
    arr[1] = 0x02;
    int y = 90;
    int y2 = 0;
    while (1)
    {
        memset(arr, 0, sizeof(arr));
        //获取终端输入的第一个字符
        char key;
        scanf(" %c", &key);
        switch (key)
        {
        case 'w':
            y++;
            arr[2] = 0x01;
            arr[3] = y;
            //向服务器发送消息
            send(cfd, arr, sizeof(arr), 0);
            break;
        case 's':
            y--;
            arr[2] = 0x01;
            arr[3] = y;
            //向服务器发送消息
            send(cfd, arr, sizeof(arr), 0);
            break;
        case 'a':
            y2++;
            arr[2] = 0x00;
            arr[3] = y2;
            //向服务器发送消息
            send(cfd, arr, sizeof(arr), 0);
            break;
        case 'd':
            y2--;
            arr[2] = 0x00;
            arr[3] = y2;
            //向服务器发送消息
            send(cfd, arr, sizeof(arr), 0);
            break;
        default:
            puts("error");
        }
    }
    //关闭客户端
    close(cfd);
    return 0;
}