#include "apue.h"#include <netdb.h>#include <errno.h>#include <sys/socket.h>#define MAXADDRLEN	256#define BUFLEN		128extern int connect_retry(int, const struct sockaddr *, socklen_t);voidprint_uptime(int sockfd){	int		n;	char	buf[BUFLEN];	while ((n = recv(sockfd, buf, BUFLEN, 0)) > 0)		write(STDOUT_FILENO, buf, n);	if (n < 0)		err_sys("recv error");}intmain(int argc, char *argv[]){	struct addrinfo	*ailist, *aip;	struct addrinfo	hint;	int				sockfd, err;	if (argc != 2)		err_quit("usage: ruptime hostname");	hint.ai_flags = 0;	hint.ai_family = 0;	hint.ai_socktype = SOCK_STREAM;	hint.ai_protocol = 0;	hint.ai_addrlen = 0;	hint.ai_canonname = NULL;	hint.ai_addr = NULL;	hint.ai_next = NULL;	if ((err = getaddrinfo(argv[1], "ruptime", &hint, &ailist)) != 0)		err_quit("getaddrinfo error: %s", gai_strerror(err));	for (aip = ailist; aip != NULL; aip = aip->ai_next) {		if ((sockfd = socket(aip->ai_family, SOCK_STREAM, 0)) < 0)			err = errno;		if (connect_retry(sockfd, aip->ai_addr, aip->ai_addrlen) < 0) {			err = errno;		} else {			print_uptime(sockfd);			exit(0);		}	}	fprintf(stderr, "can't connect to %s: %s\n", argv[1],	  strerror(err));	exit(1);}