/* @(#)tcp.c 1.4 99/02/11 Connectathon Testsuite */ /* * client for simple tcp ping program. * open connection with server, who will echo request back. */ #define TCP_PORT 3456 #include #include #include #include #include #include #include #include static void xxit(s) char *s; { perror(s); exit(1); } int main(argc, argv) int argc; char **argv; { int s, len, ret; struct sockaddr_in addr; /* socket address */ size_t addrlen = sizeof(struct sockaddr_in); struct hostent *hp; char *peer; char buf[BUFSIZ]; char *msg = "This is a test message!"; if (argc != 2) { fprintf(stderr, "usage: %s hostname\n", argv[0]); exit(1); } peer = argv[1]; if ((hp = gethostbyname(peer)) == NULL) { fprintf(stderr, "Can't find host %s\n", peer); exit(1); } if ((s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) xxit("socket"); addr.sin_family = AF_INET; addr.sin_port = htons(TCP_PORT); addr.sin_addr = *(struct in_addr *)hp->h_addr; fprintf(stderr, "Connecting to %s (%x)\n", peer, addr.sin_addr.s_addr); if (connect(s, (struct sockaddr *)&addr, addrlen) < 0) xxit("connect"); strcpy(buf, msg); len = strlen(buf); ret = write(s, buf, len); fprintf(stderr, " write ret %d (len %d)\n", ret, len); ret = read(s, buf, BUFSIZ); fprintf(stderr, " read ret %d\n", ret); if (ret != len || *buf != *msg + 1 || strcmp(buf+1, msg+1)) fprintf(stderr, "Message error: sent '%s' recv '%s'\n", msg, buf); else fprintf(stderr, "tcp ping to %s ok\n", peer); }