如何用C编写基于epoll的套接字客户端

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

#define MAX_EVENTS 10
#define MAX_BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in server_addr;
    char buffer[MAX_BUFFER_SIZE];

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(8080);
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    // 连接服务器
    if (connect(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    // 创建epoll实例
    int epollfd = epoll_create1(0);
    if (epollfd == -1) {
        perror("epoll_create1");
        exit(EXIT_FAILURE);
    }

    // 添加套接字到epoll实例中
    struct epoll_event event;
    event.events = EPOLLIN;
    event.data.fd = sockfd;
    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, sockfd, &event) == -1) {
        perror("epoll_ctl");
        exit(EXIT_FAILURE);
    }

    // 循环等待事件发生
    struct epoll_event events[MAX_EVENTS];
    while (1) {
        int num_events = epoll_wait(epollfd, events, MAX_EVENTS, -1);
        if (num_events == -1) {
            perror("epoll_wait");
            exit(EXIT_FAILURE);
        }

        // 处理事件
        for (int i = 0; i < num_events; i++) {
            if (events[i].data.fd == sockfd) {
                // 从服务器接收数据
                ssize_t num_bytes = recv(sockfd, buffer, sizeof(buffer), 0);
                if (num_bytes == -1) {
                    perror("recv");
                    exit(EXIT_FAILURE);
                } else if (num_bytes == 0) {
                    // 服务器关闭连接
                    close(sockfd);
                    exit(EXIT_SUCCESS);
                }

                // 处理接收到的数据
                printf("Received: %s\n", buffer);
            }
        }
    }

    return 0;
}