service端

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/shm.h>

#define MYPORT  8887
#define QUEUE   20
#define BUFFER_SIZE 1024

int main()
{
    ///定义sockfd
    int server_sockfd = socket(AF_INET,SOCK_STREAM, 0);

    ///定义sockaddr_in
    struct sockaddr_in server_sockaddr;
    server_sockaddr.sin_family = AF_INET;
    server_sockaddr.sin_port = htons(MYPORT);
    server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);

    ///bind，成功返回0，出错返回-1
    if(bind(server_sockfd,(struct sockaddr *)&server_sockaddr,sizeof(server_sockaddr))==-1)
    {
        perror("bind");
        exit(1);
    }

    ///listen，成功返回0，出错返回-1
    if(listen(server_sockfd,QUEUE) == -1)
    {
        perror("listen");
        exit(1);
    }

    ///客户端套接字
    char buffer[BUFFER_SIZE];
    struct sockaddr_in client_addr;
    socklen_t length = sizeof(client_addr);

    ///成功返回非负描述字，出错返回-1
    int conn = accept(server_sockfd, (struct sockaddr*)&client_addr, &length);
    if(conn<0)
    {
        perror("connect");
        exit(1);
    }

    while(1)
    {
        memset(buffer,0,sizeof(buffer));
        int len = recv(conn, buffer, sizeof(buffer),0);
        if(strcmp(buffer,"exit\n")==0)
            break;
        fputs(buffer, stdout);
        send(conn, buffer, len, 0);
    }
    close(conn);
    close(server_sockfd);
    return 0;
}

client端

#include <sys/types.h>#include <sys/socket.h>#include <stdio.h>#include <netinet/in.h>#include <arpa/inet.h>#include <unistd.h>#include <string.h>#include <stdlib.h>#include <fcntl.h>#include <sys/shm.h>#define MYPORT  8887#define BUFFER_SIZE 1024int main(){    ///定义sockfd    int sock_cli = socket(AF_INET,SOCK_STREAM, 0);    ///定义sockaddr_in    struct sockaddr_in servaddr;    memset(&servaddr, 0, sizeof(servaddr));    servaddr.sin_family = AF_INET;    servaddr.sin_port = htons(MYPORT);  ///服务器端口    servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");  ///服务器ip    ///连接服务器，成功返回0，错误返回-1    if (connect(sock_cli, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0)    {        perror("connect");        exit(1);    }    char sendbuf[BUFFER_SIZE];    char recvbuf[BUFFER_SIZE];    while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)    {        send(sock_cli, sendbuf, strlen(sendbuf),0); ///发送        if(strcmp(sendbuf,"exit\n")==0)            break;        recv(sock_cli, recvbuf, sizeof(recvbuf),0); ///接收        fputs(recvbuf, stdout);        memset(sendbuf, 0, sizeof(sendbuf));        memset(recvbuf, 0, sizeof(recvbuf));    }    close(sock_cli);    return 0;}

测试：