linux poll 驱动

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

#define MAX_EVENTS 10

int main() {
    int sockfd, newsockfd, portno;
    struct sockaddr_in serv_addr, cli_addr;
    socklen_t clilen;
    char buffer[256];
    int n;

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("ERROR opening socket");
        exit(1);
    }

    memset((char *) &serv_addr, 0, sizeof(serv_addr));
    portno = 8080;

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(portno);

    if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
        perror("ERROR on binding");
        exit(1);
    }

    listen(sockfd, 5);
    clilen = sizeof(cli_addr);

    struct pollfd fds[MAX_EVENTS];
    fds[0].fd = sockfd;
    fds[0].events = POLLIN;

    while (1) {
        int ret = poll(fds, MAX_EVENTS, -1);
        if (ret < 0) {
            perror("poll error");
            break;
        }

        if (fds[0].revents & POLLIN) {
            newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
            if (newsockfd < 0) {
                perror("ERROR on accept");
                continue;
            }
            fds[1].fd = newsockfd;
            fds[1].events = POLLIN;
        }

        for (int i = 1; i < MAX_EVENTS; i++) {
            if (fds[i].revents & POLLIN) {
                n = read(fds[i].fd, buffer, 255);
                if (n < 0) {
                    perror("ERROR reading from socket");
                    close(fds[i].fd);
                    fds[i] = fds[MAX_EVENTS - 1];
                    i--;
                } else {
                    buffer[n] = '\0';
                    printf("Here is the message: %s\n", buffer);
                }
            }
        }
    }

    close(sockfd);
    return 0;
}