select实现的TCP并发服务器

#include <myhead.h>
#define SER_PORT 8888
#define SER_IP "192.168.117.96"
 
 
 
 
int main(int argc, const char *argv[])
{
	int sfd = -1;
	sfd = socket(AF_INET,SOCK_STREAM,0);
	if(sfd == -1)
	{
		perror("socket");
		return -1;
	}
	printf("sfd = %d\n",sfd);
 
 
	int reuse = 1;
	if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse)) == -1)
	{
		perror("setsockopt");
		return -1;
	}
 
 
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(SER_PORT);
	sin.sin_addr.s_addr = inet_addr(SER_IP);
 
	if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin)) == -1)
	{
		perror("bind");
		return -1;
	}
	printf("bind success\n");
 
	if(listen(sfd,128) == -1)
	{
		perror("listen");
		return -1;
	}
	printf("listen success\n");
 
 
 
 
	int newfd = -1;
	struct sockaddr_in cin;
	socklen_t addrlen = sizeof(cin);
	char sbuf[128] = {0};
 
	fd_set readfds,tempfds;
	FD_ZERO(&readfds);
 
	FD_SET(0,&readfds);
	FD_SET(sfd,&readfds);
 
	int maxfd = sfd;
 
	struct sockaddr_in cin_arr[1024];
 
	while(1)
	{
		tempfds = readfds;
 
		int res = select(maxfd+1,&tempfds,NULL,NULL,NULL);
		if(res == -1)
		{
			perror("select");
			return -1;
		}
		else if(res == 0)
		{
			printf("time out\n");
			return -1;
		}
	
 
		for(int i = 0;i<=maxfd;i++)
		{
			if(!FD_ISSET(i,&tempfds))
			{
				continue;
			}
 
			if(i == sfd)
			{
				if((newfd = accept(sfd,(struct sockaddr*)&cin,&addrlen)) == -1)
				{
					perror("accept");
					return -1;
				}
				printf("[%s %d]:发来连接请求\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));
				cin_arr[newfd] = cin;
 
				FD_SET(newfd,&readfds);
				if(newfd > maxfd)
				{
					maxfd = newfd;
				}
			}
			else if(i == 0)
			{
				fgets(sbuf,sizeof(sbuf),stdin);
				sbuf[strlen(sbuf)-1] = 0;
				printf("触发了键盘输入事件:%s\n",sbuf);
 
				for(int i = 4;i<maxfd;i++)
				{
					send(i,sbuf,sizeof(sbuf),0);
				}
				printf("发送成功\n");
			}
			else
			{
				char rbuf[128] = {0};
 
				bzero(rbuf,sizeof(rbuf));
				int res = recv(i,rbuf,sizeof(rbuf)-1,0);
				if(res == 0)
				{
					printf("客户端已经下线\n");
 
					close(i);
 
					FD_CLR(i,&readfds);
 
					for(int k = maxfd;k >= sfd;k--)
					{
						if(FD_ISSET(k,&readfds))
						{
							maxfd = k;
							break;
						}
					}
					continue;
				}
				printf("[%s %d]:%s\n",inet_ntoa(cin_arr[i].sin_addr),ntohs(cin_arr[i].sin_port),rbuf);
				strcat(rbuf,">_<");
 
				send(i,rbuf,strlen(rbuf),0);
				printf("发送成功\n");
			}
		}
	}
 
 
	close(sfd);
 
 
	return 0;
}