/*********************************************************************************
 *      Copyright:  (C) 2025 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  poll.c
 *    Description:  This file is poll example.
 *
 *        Version:  1.0.0(11/06/2025)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/06/2025 10:33:45 AM"
 *
 ********************************************************************************/
#include <stdio.h>
#include <poll.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define MAX_FDS     2 /*  监听 STDIN + sockfd */

int main(void)
{
	int                 sockfd;
	struct sockaddr_in  addr;
	int                 ret;
	int                 reuse = 1;
	struct pollfd       fds[MAX_FDS];

	sockfd = socket(AF_INET, SOCK_STREAM, 0); /* 创建套接字 */

	addr.sin_family = AF_INET;
	addr.sin_port = htons(8888);
	addr.sin_addr.s_addr = INADDR_ANY;

	setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
	bind(sockfd, (struct sockaddr *)&addr, sizeof(addr));
	listen(sockfd, 5);

	/* 监听标准输入(键盘)是否有数据 */
	fds[0].fd = STDIN_FILENO;
	fds[0].events = POLLIN;

	/* 监听 socket 是否有新连接 */
	fds[1].fd = sockfd;
	fds[1].events = POLLIN;

	printf("poll() monitor socket[8888] and stdin now...\n");

	while (1)
	{
		/* 调用 poll 等待事件发生 */
		ret = poll(fds, MAX_FDS, 10000);
		if (ret == -1)
		{
			perror("poll error");
			break;
		}
		else if (ret == 0)
		{
			printf("timeout...\n");
			continue;
		}

		/* 程序走到这里说明ret>0，即监听的文件描述符中有事件发生了. */

		/* 检查标准输入是否可读 */
		if (fds[0].revents & POLLIN)
		{
			char buf[128];
			read(STDIN_FILENO, buf, sizeof(buf));
			printf("You typed in keyboard: %s\n", buf);
		}

		/* 检查监听 socket 是否有连接到来 */
		if (fds[1].revents & POLLIN)
		{
			int client = accept(sockfd, NULL, NULL);
			printf("Accept and close connection: %d\n", client);
			close(client);
		}
	}

	close(sockfd);
	return 0;
}