#include "unp.h" int main(int argc, char **argv) { int sockfd, n; char recvline[MAXLINE + 1]; struct sockaddr_in servaddr; struct in_addr **pptr, *addrs[2]; struct hostent *hp; struct servent *sp; if (argc != 3) err_quit("usage: daytimetcpcli2 "); bzero(&servaddr, sizeof(servaddr)); servaddr.sin_family = AF_INET; if (inet_pton(AF_INET, argv[1], &servaddr.sin_addr) == 1) { addrs[0] = &servaddr.sin_addr; addrs[1] = NULL; pptr = &addrs[0]; } else if ( (hp = gethostbyname(argv[1])) != NULL) { pptr = (struct in_addr **) hp->h_addr_list; } else err_quit("hostname error for %s: %s", argv[1], hstrerror(h_errno)); if ( (n = atoi(argv[2])) > 0) servaddr.sin_port = htons(n); else if ( (sp = getservbyname(argv[2], "tcp")) != NULL) servaddr.sin_port = sp->s_port; else err_quit("getservbyname error for %s", argv[2]); for ( ; *pptr != NULL; pptr++) { sockfd = Socket(AF_INET, SOCK_STREAM, 0); memmove(&servaddr.sin_addr, *pptr, sizeof(struct in_addr)); printf("trying %s\n", Sock_ntop((SA *) &servaddr, sizeof(servaddr))); if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) == 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); }