简单的C++ 的socket代码展示

### 回答1：

C 语言的 socket 编程可以通过大量的示例代码来学习。下面是一个简单的 socket 代码的展示：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

int main()
{
struct addrinfo hints;
struct addrinfo *res;

memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;

getaddrinfo("www.example.com", "http", &hints, &res);

int sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
connect(sockfd, res->ai_addr, res->ai_addrlen);

// 发送信息
char *msg = "GET / HTTP/1.1\r\n\r\n";
int len;
len = send(sockfd, msg, strlen(msg), 0);

// 接受数据
char buf[4096];
len = recv(sockfd, buf, 4096, 0);
buf[len] = '\0';

printf("Received: %s", buf);

close(sockfd);

return 0;
}

### 回答2：
下面是一个简单的C语言的socket代码展示：

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

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[BUFFER_SIZE] = {0};

    // 创建 socket 文件描述符
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // 设置 socket 选项，以允许地址重用
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt failed");
        exit(EXIT_FAILURE);
    }

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

    // 将 socket 绑定到指定的地址和端口
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 监听传入的连接
    if (listen(server_fd, 3) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    // 接受连接并创建新的套接字
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {
        perror("accept failed");
        exit(EXIT_FAILURE);
    }

    // 从客户端读取数据到缓冲区
    valread = read(new_socket, buffer, BUFFER_SIZE);
    printf("%s\n", buffer);

    // 向客户端发送响应消息
    char *response = "Hello from server";
    send(new_socket, response, strlen(response), 0);
    printf("Response sent\n");

    // 关闭连接
    close(new_socket);
    close(server_fd);

    return 0;
}

此代码实现了一个简单的TCP服务器，它会创建一个监听指定端口的socket，并接受来自客户端的连接。一旦有连接建立，它会从客户端读取数据并发送响应消息。

注意：为了使此代码正常工作，您需要具备一些基础的网络编程知识。此外，在运行代码之前，请确保端口8080未被其他程序占用。

### 回答3：
下面是一个简单的使用C语言的Socket编程的示例代码：

// server.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    char buffer[BUFFER_SIZE] = {0};
    char *hello = "Hello from server";

    // 创建套接字
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
    
    // 设置套接字选项
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt failed");
        exit(EXIT_FAILURE);
    }
    
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);
    
    // 绑定套接字到指定端口
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }
    
    // 监听套接字，等待客户端连接
    if (listen(server_fd, 3) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }
    
    // 接受客户端连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {
        perror("accept failed");
        exit(EXIT_FAILURE);
    }
    
    // 读取客户端消息
    valread = read(new_socket, buffer, BUFFER_SIZE);
    printf("%s\n", buffer);
    // 向客户端发送消息
    send(new_socket, hello, strlen(hello), 0);
    printf("Hello message sent\n");
    
    return 0;
}

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

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sock = 0, valread;
    struct sockaddr_in serv_addr;
    char *hello = "Hello from client";
    char buffer[BUFFER_SIZE] = {0};

    // 创建套接字
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
    
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);
    
    // 将IP地址从点分十进制转换为二进制
    if (inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr) <= 0) {
        perror("invalid address or address not supported");
        exit(EXIT_FAILURE);
    }
    
    // 连接服务器
    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        perror("connection failed");
        exit(EXIT_FAILURE);
    }
    
    // 向服务器发送消息
    send(sock, hello, strlen(hello), 0);
    printf("Hello message sent\n");
    
    // 读取服务器消息
    valread = read(sock, buffer, BUFFER_SIZE);
    printf("%s\n", buffer);
    
    return 0;
}

这里提供了服务器端和客户端的代码示例。服务器端使用socket创建套接字，设置选项，绑定端口，监听连接，接受连接，读取客户端消息，然后向客户端发送消息。客户端通过socket创建套接字，设置服务器的地址和端口，连接服务器，然后向服务器发送消息，最后读取服务器的响应消息。这样就实现了一个简单的C语言Socket通信示例。