#include "apue.h" #include #include #include #define MAXADDRLEN 256 #define BUFLEN 128 extern int connect_retry(int, const struct sockaddr *, socklen_t); void print_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"); } int main(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); }