select.c：

#include <myhead.h>

#define ERR_MSG(msg) do{\
	fprintf(stderr,"__%d__:",__LINE__);\
	perror(msg);\
}while(0)

#define IP "192.168.1.3"
#define PORT 8888

int main(int argc, const char *argv[])
{
	//创建报式套接字socket
	int sfd=socket(AF_INET,SOCK_STREAM,0);
	if(-1==sfd){
		ERR_MSG("socket error");
		return -1;
	}
	printf("socket success\n");

	//允许端口快速复用setsockopt
	int reuse=1;
	if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))){
		ERR_MSG("setsockopt error");
		return -1;
	}

	//定义一个地址结构体
	struct sockaddr_in sin;
	sin.sin_family 		= AF_INET;
	sin.sin_port 		= htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);

	//将套接字和IP、端口绑定bind
	if(-1==bind(sfd,(struct sockaddr*)&sin,sizeof(sin))){
		ERR_MSG("bind error");
		return -1;
	}
	printf("bind success\n");

	//将套接字设置成被动监听状态
	if(-1==listen(sfd,128)){
		ERR_MSG("listen error");
		return -1;
	}

	int newfd=-1;

	fd_set readfds,tempfds;

	FD_ZERO(&readfds);
	FD_ZERO(&tempfds);

	FD_SET(0,&readfds);
	FD_SET(sfd,&readfds);

	int maxfd=sfd;
	struct sockaddr_in saveCin[1024];

	int s_res=0;
	ssize_t res=0;

	char buf[128]="";

	struct sockaddr_in cin;
	socklen_t addrlen=sizeof(cin);

	while(1){
		tempfds=readfds;

		s_res=select(maxfd+1,&tempfds,NULL,NULL,NULL);
		if(-1==s_res){
			ERR_MSG("select error");
			return -1;
		}
		else if(0==s_res){
			printf("time out...\n");
			return -1;
		}

		for(int i=0;i<=maxfd;i++){
			if(!FD_ISSET(i,&tempfds)){
				continue;
			}
			if(0==i){
				printf("触发键盘输入事件>>>\n");
				bzero(buf,sizeof(buf));
				fgets(buf,sizeof(buf),stdin);
				buf[strlen(buf)-1]=0;
				printf(":%s\n",buf);
			}
			else if(sfd==i){
				printf("触发客户端连接事件>>>\n");
				if((newfd=accept(sfd,(struct sockaddr*)&cin,&addrlen)) == -1){
					ERR_MSG("accept");
					return -1;
				}
				printf("[%s:%d] newfd=%d 连接成功\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);

				saveCin[newfd]=cin;

				FD_SET(newfd,&readfds);
				maxfd = maxfd>newfd ? maxfd : newfd;
			}
			else{
				printf("触发客户端交互事件>>>\n");
				bzero(buf,sizeof(buf));

				res = recv(i,buf,sizeof(buf),0);
				if(-1 == res){
					ERR_MSG("recv");
					return -1;
				}
				else if(0 == res){
					printf("[%s:%d] newfd=%d 下线了\n",inet_ntoa(saveCin[i].sin_addr),ntohs(saveCin[i].sin_port),i);

					close(i);

					FD_CLR(i,&readfds);

					while(FD_ISSET(maxfd,&readfds) == 0 && maxfd-->=0);
					continue;
				}
				printf("[%s:%d] newfd=%d : %s\n",inet_ntoa(saveCin[i].sin_addr),ntohs(saveCin[i].sin_port),i,buf);

				strcat(buf,"*-*");
				if(send(i,buf,sizeof(buf),0) == -1){
					ERR_MSG("send");
					return -1;
				}
				printf("发送成功\n");
			}
		}
	}
	close(sfd);
	
	return 0;
}

效果图：