linux TCP通信实现 服务器端 - 客户端

合集 - 网络编程(16)

1.linux socket地址2023-10-112.linux IP 地址转换2023-10-113.linux TCP 通信流程 套接字函数 socket() bind() listen() accept() connect()2023-10-12

4.linux TCP通信实现 服务器端 - 客户端2023-10-12

5.linux TCP 三次握手2023-10-126.linux TCP滑动窗口 四次挥手2023-10-227.linux 多进程实现并发服务器 多线程并发2023-10-248.linux TCP状态转换 半关闭 shutdown netstat 端口复用 setsockopt2023-10-249.linux IO多路复用 select poll epoll2023-10-2510.linux 多路复用---poll2023-10-3011.linux 多路复用---epoll2023-10-3112.linux UDP 通信2023-11-0313.linux 本地套接字通信2023-11-0314.linux Web服务器以及HTTP协议2023-11-0815.linux 服务器编程基本框架和两种高效事件的处理模式2023-11-1016.linux 线程池 EPOLLONESHOT事件2023-11-13

收起

服务器端： 

//TCP通信的服务器端

#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
int main()
{
    //1.创建 socket(用于监听的套接字)
    int lfd = socket(AF_INET, SOCK_STREAM, 0);//IPv4 流式协议 TCP  lfd = 获取的文件描述符
    if(lfd == -1)
    {
        perror("socket");
        exit(-1);
    }
    //2.绑定 
    struct sockaddr_in saddr;
    //初始化  否则创建的变量会自动被赋予随机值
    saddr.sin_family = AF_INET;//AF_INET 与 PF_INET值相等
    //inet_pton(AF_INET, "192.168.192.128", saddr.sin_addr.s_addr);// 主机字节序转换为网络字节序
    saddr.sin_addr.s_addr = INADDR_ANY; // 0.0.0.0      INADDR_ANY宏值为0
    saddr.sin_port = htons(9999);//主机字节序9999通过 htons转换为网络字节序
    int ret = bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr));
    if(ret == -1)
    {
        perror("bind");
        exit(-1);
    }
    //3.监听
    ret = listen(lfd, 8);
    if(ret == -1)
    {
        perror("listen");
        exit(-1);
    }
    //4.接收客户端连接
    struct sockaddr_in clientaddr;//客户端地址
    socklen_t len = sizeof(clientaddr);
    int cfd = accept(lfd, (struct sockaddr *)&clientaddr, &len);
    if(cfd == -1)
    {
        perror("accept");
        exit(-1);
    }
    //输出客户端的信息
    char clientIP[16];
    inet_ntop(AF_INET, &clientaddr.sin_addr.s_addr, clientIP, sizeof(clientIP));
    unsigned short clientPort = ntohs(clientaddr.sin_port);
    printf("client ip is %s, port is %d\n", clientIP, clientPort);
    //5.通信 
    //服务器端先接收数据后返回数据
    //获取客户的数据
    char recvBuf[1024] = {0};
    int len = read(cfd, recvBuf, sizeof(recvBuf));
    if( len == -1)
    {
        perror("read");
        exit(-1);
    }
    else if(len > 0)
    {
        printf("recv client data: %s\n",recvBuf);
    }
    else if( len == 0)
    {
        //表示客户端断开连接
        printf("client closed...\n");
    }
    //给客户端发送数据
    char * data = "hello, i am server";
    write(cfd, data, strlen(data));
    //6.关闭文件描述符
    close(cfd);
    close(lfd);
    return 0;
}

客户端：

//TCP通信的客户端

#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
int main()
{
    //1.创建套接字
    int fd = socket(AF_INET, SOCK_STREAM, 0);
    if(fd == -1)
    {
        perror("socket");
        exit(-1);
    }
    //2.连接服务器端
    struct sockaddr_in serveraddr;
    serveraddr.sin_family = AF_INET;
    inet_pton(AF_INET, "10.0.8.5", &serveraddr.sin_addr.s_addr);//本机 ip
    serveraddr.sin_port = htons(9999);
    int ret = connect(fd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
    if(ret == -1)
    {
        perror("connect");
        exit(-1);
    }
    //3.通信
    char recvBuf[1024] = {0};
    while(1)
    {
        char * data = "hello, i am client";
        //给服务器端发送数据
        write(fd, data, strlen(data));
        sleep(1);
        //读取数据
        int len = read(fd, recvBuf, sizeof(recvBuf));
        if(len == -1)
        {
            perror("read");
            exit(-1);
        }
        else if(len > 0)
        {
            printf("recv server data: %s\n",recvBuf);
        }
        else if(len == 0)
        {
            //表示客户端断开连接
            printf("server closed...\n");
            break;
        }
    }
    //关闭连接
    close(fd);
    return 0;
}