Linux系统编程多路复用poll

服务器代码

#include <stdio.h>
#include <poll.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdlib.h>
#include <error.h>
#include <errno.h>
#define maxsize 1024
#define PORT 8888
struct sockaddr_in server,client;
int listen_socket;
int len;
struct pollfd poll_fd[maxsize];
void socket_init()
{
	server.sin_family = AF_INET;
	server.sin_port = htons(PORT);
	server.sin_addr.s_addr = htonl(0);
	listen_socket=socket(AF_INET,SOCK_STREAM,0);
   	if(listen_socket < 0)  
   	{ 
      		perror("socket:");
      		exit(1);   
   	}
	if(bind(listen_socket,(struct sockaddr *)&server,sizeof(server)) < 0)
   	{
      		perror("bind:");
      		exit(1);
   	}
	if(listen(listen_socket,128) < 0)
	{
		perror("listen:");
		exit(1);
	}
	printf("this is sever\n");
	printf("服务器初始化完成!\n");

}
int main()
{
	int i,max,ret;
	char recbuf[1024],sendbuf[1024];
	len=sizeof(client);
	socket_init();
	poll_fd[0].fd=listen_socket;
	poll_fd[0].events=POLLRDNORM;
	for(i=1;i<maxsize;i++) poll_fd[i].fd=-1;
	max=1;
	while(1)
	{
		poll(poll_fd,max,-1);
		if(poll_fd[0].revents & POLLRDNORM) //判断有没有新的客户端连接
		{
			for(i=1;i<maxsize;i++)
			{
				if(poll_fd[i].fd ==-1)
				{
					poll_fd[i].fd=accept(listen_socket,(struct sockaddr *)&client,&len);
					poll_fd[i].events = POLLRDNORM;
					printf("客户机%d已连接\n",poll_fd[i].fd);
					max++;
					break;
				}
			}
		}

		for(i=1;i<maxsize;i++) //判断客户端有没有数据发来
		{
			if(poll_fd[i].revents & POLLRDNORM)
			{
				
				ret=read(poll_fd[i].fd,recbuf,sizeof(recbuf));
				if(ret==0)
				{
					printf("客户机%d已断开连接\n",poll_fd[i].fd);
					close(poll_fd[i].fd);
					poll_fd[i].fd=-1;
					continue;
				}
				printf("客户机%d：%s\n",poll_fd[i].fd,recbuf);
				strcpy(sendbuf,recbuf);
				write(poll_fd[i].fd,sendbuf,sizeof(sendbuf));
			}
		}
	}
	close(listen_socket);
	return 0;
}

客户端代码

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

#define PORT 8888    
int socket_fd;       
struct sockaddr_in server;    


void socket_init()
{
  server.sin_family = AF_INET; 
  server.sin_port = htons(PORT);  
  server.sin_addr.s_addr = inet_addr("127.0.0.1");
  socket_fd = socket(AF_INET,SOCK_STREAM,0);
  if(socket_fd < 0)
  {
     	perror("socket:");
     	exit(1);
  }
  if(connect(socket_fd,(struct sockaddr *)&server,sizeof(server))<0)
  {
     perror("connect:");
     exit(1);
  }
}


int main()
{
  	char sendbuf[1024],recbuf[1024];
  	printf("this is client\n");
  	socket_init();
  	while(1)
  	{
    	scanf("%s",sendbuf);
    	if(write(socket_fd,sendbuf,sizeof(sendbuf))<0)
    	{
       		perror("write:");
       		exit(1);
    	}
    	if(read(socket_fd,recbuf,sizeof(recbuf))<0)
    	{
         	perror("read:");
         	exit(1);
    	}
    	printf("%s\n",recbuf);
  	}
  close(socket_fd);
  return 0;
}