作业
1>    使用select完成TCP客户端程序

//client
#include<myhead.h>
#define CLINET_IP "192.168.125.79"
#define CLINET_PORT 9999
#define SERVE_IP "192.168.125.79"
#define SERVE_PORT 8888
int main(int argc, const char *argv[])
{
	//socket()
	int cfd=-1;
	if((cfd=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("socket error");
		return -1;
	}
	printf("cfd=%d\n",cfd);
	int reuse=1;
	if(setsockopt(cfd, SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))==-1)
	{
		perror("setsockopt error");
		return -1;
	}
	//(bind())
	struct sockaddr_in cin;
	cin.sin_family=AF_INET;
	cin.sin_port=htons(CLINET_PORT);
	cin.sin_addr.s_addr=inet_addr(CLINET_IP);
	if(bind(cfd,(struct sockaddr*)&cin,sizeof(cin))==-1)
	{
		perror("bind error");
		return -1;
	}
	printf("[%s:%d]->绑定成功\n",CLINET_IP,CLINET_PORT);
	//connect()
	struct sockaddr_in 	sin;
	sin.sin_family=AF_INET;
	sin.sin_port=htons(SERVE_PORT);
	sin.sin_addr.s_addr=inet_addr(SERVE_IP);
	if(connect(cfd,(struct sockaddr*)&sin,sizeof(sin))==-1)
	{
		perror("connect error");
		return -1;
	}
	printf("[%s:%d]->连接成功\n",SERVE_IP,SERVE_PORT);
	//recv()/send()
	char buf[128]="";
	fd_set readfds;//定义文件描述符集合
	FD_ZERO(&readfds);//清空集合
	FD_SET(0,&readfds);//放入集合
	FD_SET(cfd,&readfds);//放入集合
	int res1=-1;//接收select返回
	int res2=-1;//接收recv返回
	fd_set tempfds;//定义一个临时文件描述符集合
	while(1)	
	{
		tempfds=readfds;
		res1=select(cfd+1,&tempfds,NULL,NULL,NULL);
		if(res1==-1)
		{
			perror("select error");
			return -1;
		}
		else if(res1==0)
		{
			printf("time out\n");
			return -1;
		}
	
		if(FD_ISSET(0,&tempfds))
		{
			bzero(buf,sizeof(buf));
			fgets(buf,sizeof(buf),stdin);
			buf[strlen(buf)-1]=0;
			send(cfd,buf,sizeof(buf),0);
		}
		if(FD_ISSET(cfd,&tempfds))
		{
			bzero(buf,sizeof(buf));
			 res2=recv(cfd,buf,sizeof(buf),0);
			if(res2==0||strcmp(buf,"quit")==0)
			{
				printf("服务器下线\n");
				break;
			}
			printf("[%s:%d]->%s\n",SERVE_IP,SERVE_PORT,buf);
		}
	}
	//close()
	close(cfd);
	return 0;
}

//serve
#include<myhead.h>
#define PORT 8888
#define IP "192.168.125.79"
int main(int argc, const char *argv[])
{
	int sfd=-1;
	if((sfd=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("socket error");
		return -1;
	}
	printf("sfd=%d\n",sfd);
	int reuse=1;
	if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))==-1)
	{
		perror("setsockopt error");
		return -1;
	}
	struct sockaddr_in sin;
	sin.sin_family=AF_INET;
	sin.sin_port=htons(PORT);
	sin.sin_addr.s_addr=inet_addr(IP);
	if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin))==-1)
	{
		perror("bind error");
		return -1;
	}
	printf("bind success _%d_%s_%s\n",__LINE__,__FILE__,__func__);
	if(listen(sfd,128)==-1)
	{
		perror("listen error");
		return -1;
	}
	printf("listen success _%d_%s_%s\n",__LINE__,__FILE__,__func__);
	struct sockaddr_in cin;
	socklen_t socklen=sizeof(cin);
	fd_set readfds;	//定义阻塞的文件描述符集合
	FD_ZERO(&readfds);	//清空
	FD_SET(sfd,&readfds);	//将文件描述符放入
	FD_SET(0,&readfds);
	int res=0;//select返回值
	int maxfd=sfd;
	int newfd=-1;
	char buf[128]="";
	char rbuf[128]="";//服务器客户端通信
	struct sockaddr_in arr_cin[1024];
	fd_set tempfds;
	while(1)
	{
		tempfds=readfds;
		res=select(maxfd+1,&tempfds,NULL,NULL,NULL);
		if(res==-1)
		{
			perror("select error");
			return -1;
		}
		else if(res ==0)
		{
			printf("time out\n");
			return -1;
		}
		else
		{	
			for(int index=0;index<=maxfd;index++)
			{
				if(!FD_ISSET(index,&tempfds))//所有文件描述符没有事件发生	
				{
					continue;
				}
				else if( index==sfd )
				{
					if((newfd=accept(sfd,(struct sockaddr*)&cin,&socklen))==-1)
					{
						perror("accept error");
						return -1;
					}
					arr_cin[newfd]=cin;
					printf("[%s:%d]:连接成功,newfd=%d\n",inet_ntoa(arr_cin[index].sin_addr),ntohs(arr_cin[index].sin_port),newfd);
					FD_SET(newfd,&readfds);//新的newfd应当加入原本的readfds
					if(newfd>maxfd)
					{
						maxfd=newfd;
					}
				}
				else if( index==0 )
				{
					scanf("%s",buf);
					printf("将发送所有连接的用户->%s\n",buf);
					for(int j=4;j<=maxfd;j++)
					{
					send(j,buf,sizeof(buf),0);
					}
				}
				else
				{
					bzero(rbuf,sizeof(rbuf));
					if(recv(index,rbuf,sizeof(rbuf),0)==0)
					{
						printf("客户端下线\n");
						close(index);//关闭套接字文件
						FD_CLR(index,&tempfds);//移除select数组
						for(int i=maxfd;i>0;i--)
						{
							if(FD_ISSET(i,&readfds))
							{
								maxfd=i;
								break;
							}
						}
						continue;
					}
					printf("[%s:%d]:%s\n",inet_ntoa(arr_cin[index].sin_addr),ntohs(arr_cin[index].sin_port),rbuf);
					strcat(rbuf,"^_^");
					send(index,rbuf,sizeof(rbuf),0);
				}
			}
		}
	}
	close(sfd);
	return 0;
}

2>    使用poll完成TCP并发服务器