建立两台ubuntu虚拟机使用socket通讯的代码，客户端和服务端分开写，用c语言写

### 回答1：
以下是基于C语言实现的简单的客户端和服务端的socket通讯代码示例，使用的是TCP协议。

服务端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define PORT 8888
#define MAXLINE 1024

int main() {
    int listenfd, connfd;
    struct sockaddr_in servaddr, cliaddr;
    socklen_t cliaddr_len = sizeof(cliaddr);
    char buf[MAXLINE];
    char *hello = "Hello from server";

    // 创建socket
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    if (listenfd < 0) {
        perror("socket creation failed");
        exit(EXIT_FAILURE);
    }

    memset(&servaddr, 0, sizeof(servaddr));

    // 绑定IP和端口
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(PORT);

    if ((bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr))) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 监听
    if ((listen(listenfd, 5)) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    printf("Server listening on port %d...\n", PORT);

    while (1) {
        // 接收连接请求
        connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &cliaddr_len);
        if (connfd < 0) {
            perror("accept failed");
            exit(EXIT_FAILURE);
        }

        // 接收客户端发送的消息
        memset(buf, 0, sizeof(buf));
        if (read(connfd, buf, MAXLINE) < 0) {
            perror("read failed");
            exit(EXIT_FAILURE);
        }

        printf("Message received from client: %s\n", buf);

        // 发送欢迎消息到客户端
        if (write(connfd, hello, strlen(hello)) < 0) {
            perror("write failed");
            exit(EXIT_FAILURE);
        }

        close(connfd);
    }

    return 0;
}

客户端代码：

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

#define PORT 8888
#define MAXLINE 1024

int main() {
    int sockfd;
    struct sockaddr_in servaddr;
    char *hello = "Hello from client";
    char buf[MAXLINE];

    // 创建socket
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("socket creation failed");
        exit(EXIT_FAILURE);
    }

    memset(&servaddr, 0, sizeof(servaddr));

    // 设置服务端的IP和端口
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    servaddr.sin_port = htons(PORT);

    // 连接服务端
    if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) {
        perror("connection failed");
        exit(EXIT_FAILURE);
    }

    // 发送消息到服务端
    if (write(sockfd, hello, strlen(hello)) < 0) {
        perror("write failed");
        exit(EXIT_FAILURE);
    }

    printf("Message sent to server: %s\n", hello);

    // 接收服务端发送的消息
    memset(buf, 0, sizeof(buf));
    if (read(sockfd, buf, MAXLINE) < 0) {
        perror("read failed");
        exit(EXIT_FAILURE);
    }

    printf("Message received from server: %s\n", buf);

    close(sockfd);

    return 0;
}

注意：这只是一个简单的示例，实际使用中需要进行错误处理和异常处理。

### 回答2：
以下是基于C语言编写的通过Socket通信的Ubuntu虚拟机的客户端和服务端代码：

客户端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    char buffer[BUFFER_SIZE];
    struct sockaddr_in serv_addr;

    // 创建套接字
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        printf("套接字创建失败\n");
        exit(EXIT_FAILURE);
    }

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);

    // 将IP地址从字符串转换为二进制形式
    if (inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr) <= 0) {
        printf("无效的IP地址\n");
        exit(EXIT_FAILURE);
    }

    // 连接服务器
    if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        printf("连接失败\n");
        exit(EXIT_FAILURE);
    }

    // 发送数据
    strcpy(buffer, "Hello from client");
    send(sockfd, buffer, strlen(buffer), 0);
    printf("已发送数据到服务器: %s\n", buffer);

    // 从服务器接收数据
    memset(buffer, 0, sizeof(buffer));
    recv(sockfd, buffer, sizeof(buffer), 0);
    printf("从服务器接收到的数据: %s\n", buffer);

    close(sockfd);

    return 0;
}

服务端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int server_fd, new_socket;
    char buffer[BUFFER_SIZE];
    struct sockaddr_in address;
    int addrlen = sizeof(address);

    // 创建套接字
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        printf("套接字创建失败\n");
        exit(EXIT_FAILURE);
    }

    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    // 绑定地址和端口
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        printf("绑定失败\n");
        exit(EXIT_FAILURE);
    }

    // 监听连接
    if (listen(server_fd, 3) < 0) {
        printf("监听失败\n");
        exit(EXIT_FAILURE);
    }

    // 接受连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        printf("接受连接失败\n");
        exit(EXIT_FAILURE);
    }

    // 从客户端接收数据
    memset(buffer, 0, sizeof(buffer));
    recv(new_socket, buffer, sizeof(buffer), 0);
    printf("从客户端接收到的数据: %s\n", buffer);

    // 发送数据到客户端
    strcpy(buffer, "Hello from server");
    send(new_socket, buffer, strlen(buffer), 0);
    printf("已发送数据到客户端: %s\n", buffer);

    close(new_socket);
    close(server_fd);

    return 0;
}

以上是一个简单的Socket通信示例，其中客户端向服务端发送"Hello from client"，服务端接收并发送"Hello from server"作为回复。