#include "unp.h" int main(int argc, char **argv) { int sockfd, n; char recvline[MAXLINE + 1]; struct sockaddr_in servaddr; struct sockaddr_in6 servaddr6; struct sockaddr *sa; socklen_t salen; struct in_addr **pptr; struct hostent *hp; struct servent *sp; if (argc != 3) err_quit("usage: daytimetcpcli3 "); if ( (hp = gethostbyname(argv[1])) == NULL) err_quit("hostname error for %s: %s", argv[1], hstrerror(h_errno)); if ( (sp = getservbyname(argv[2], "tcp")) == NULL) err_quit("getservbyname error for %s", argv[2]); pptr = (struct in_addr **) hp->h_addr_list; for ( ; *pptr != NULL; pptr++) { sockfd = Socket(hp->h_addrtype, SOCK_STREAM, 0); if (hp->h_addrtype == AF_INET) { sa = (SA *) &servaddr; salen = sizeof(servaddr); } else if (hp->h_addrtype == AF_INET6) { sa = (SA *) &servaddr6; salen = sizeof(servaddr6); } else err_quit("unknown addrtype %d", hp->h_addrtype); bzero(sa, salen); sa->sa_family = hp->h_addrtype; sock_set_port(sa, salen, sp->s_port); sock_set_addr(sa, salen, *pptr); printf("trying %s\n", Sock_ntop(sa, salen)); if (connect(sockfd, sa, salen) == 0) break; /* success */ err_ret("connect error"); close(sockfd); } if (*pptr == NULL) err_quit("unable to connect"); while ( (n = Read(sockfd, recvline, MAXLINE)) > 0) { recvline[n] = 0; /* null terminate */ Fputs(recvline, stdout); } exit(0); }