/* tclient.c - simple client for TCP/IP sockets */ /* Connect to the server whose hostname or IP is given as an argument, at port 1234. Once connected, copy everything on stdin to the socket, then exit. */ #include #include #include #include #include #include #include "sockutil.h" /* some utility functions */ int main(int argc, char ** argv) { struct sockaddr_in address; struct in_addr inaddr; struct hostent * host; int sock; if (argc != 2) { fprintf(stderr, "only a single argument is supported\n"); return 1; } /* If the argument can be converted to an IP, do so. If not, try to look it up in DNS. */ if (inet_aton(argv[1], &inaddr)) host = gethostbyaddr((char *) &inaddr, sizeof(inaddr), AF_INET); else host = gethostbyname(argv[1]); if (!host) { /* We can't find an IP number */ herror("error looking up host"); exit(1); } if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) die("socket"); address.sin_family = AF_INET; address.sin_port = htons(1234); /* Take the first IP address associated with this hostname */ memcpy(&address.sin_addr, host->h_addr_list[0], sizeof(address.sin_addr)); if (connect(sock, (struct sockaddr *) &address, sizeof(address))) die("connect"); copyData(0, sock); close(sock); return 0; }