C语言网络编程：嵌入式系统中的网络通信实现

int socket(int domain, int type, int protocol);
int bind(int sockfd, struct sockaddr *addr, socklen_t addrlen);
int listen(int sockfd, int backlog);
int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
int send(int sockfd, const void *buf, size_t len, int flags);
int recv(int sockfd, void *buf, size_t len, int flags);

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

int main() {
    // 创建套接字
    int server_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (server_fd == -1) {
        perror("socket() failed");
        return EXIT_FAILURE;
    }

    // 设置服务器地址和端口
    struct sockaddr_in server_addr;
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(8080);

    // 绑定套接字到地址和端口
    if (bind(server_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("bind() failed");
        return EXIT_FAILURE;
    }

    // 监听套接字，最多同时处理5个连接
    if (listen(server_fd, 5) == -1) {
        perror("listen() failed");
        return EXIT_FAILURE;
    }

    // 循环接收连接请求并处理客户端数据
    while (1) {
        // 接受连接请求
        struct sockaddr_in client_addr;
        socklen_t client_addr_len = sizeof(client_addr);
        int client_fd = accept(server_fd, (struct sockaddr *)&client_addr, &client_addr_len);
        if (client_fd == -1) {
            perror("accept() failed");
            return EXIT_FAILURE;
        }

        // 接收客户端发送的数据
        char buf[1024];
        int recv_len = recv(client_fd, buf, sizeof(buf), 0);
        if (recv_len == -1) {
            perror("recv() failed");
            return EXIT_FAILURE;
        }

        // 发送响应数据回客户端
        char *resp = "Hello client!";
        int send_len = send(client_fd, resp, strlen(resp), 0);
        if (send_len == -1) {
            perror("send() failed");
            return EXIT_FAILURE;
        }

        // 关闭客户端套接字
        close(client_fd);
    }

    // 关闭服务器套接字
    close(server_fd);

    return EXIT_SUCCESS;
}