#include	"opend.h"#include	<sys/time.h>#include	<sys/select.h>voidloop(void){	int		i, n, maxfd, maxi, listenfd, clifd, nread;	char	buf[MAXLINE];	uid_t	uid;	fd_set	rset, allset;	FD_ZERO(&allset);	/* obtain fd to listen for client requests on */	if ((listenfd = serv_listen(CS_OPEN)) < 0)		log_sys("serv_listen error");	FD_SET(listenfd, &allset);	maxfd = listenfd;	maxi = -1;	for ( ; ; ) {		rset = allset;	/* rset gets modified each time around */		if ((n = select(maxfd + 1, &rset, NULL, NULL, NULL)) < 0)			log_sys("select error");		if (FD_ISSET(listenfd, &rset)) {			/* accept new client request */			if ((clifd = serv_accept(listenfd, &uid)) < 0)				log_sys("serv_accept error: %d", clifd);			i = client_add(clifd, uid);			FD_SET(clifd, &allset);			if (clifd > maxfd)				maxfd = clifd;	/* max fd for select() */			if (i > maxi)				maxi = i;	/* max index in client[] array */			log_msg("new connection: uid %d, fd %d", uid, clifd);			continue;		}		for (i = 0; i <= maxi; i++) {	/* go through client[] array */			if ((clifd = client[i].fd) < 0)				continue;			if (FD_ISSET(clifd, &rset)) {				/* read argument buffer from client */				if ((nread = read(clifd, buf, MAXLINE)) < 0) {					log_sys("read error on fd %d", clifd);				} else if (nread == 0) {					log_msg("closed: uid %d, fd %d",					  client[i].uid, clifd);					client_del(clifd);	/* client has closed cxn */					FD_CLR(clifd, &allset);					close(clifd);				} else {	/* process client's request */					request(buf, nread, clifd, client[i].uid);				}			}		}	}}