/* * Connects to the local host at port 1234. */ #include #include #include #include #include #define NSTRS 3 /* no. of strings */ /* * Strings we send to the server. */ char *strs[NSTRS] = { "This is the first string from the client.\n", "This is the second string from the client.\n", "This is the third string from the client.\n" }; extern int errno; main() { char c; FILE *fp; char hostname[64]; register int i, s; struct hostent *hp; struct sockaddr_in sin; /* * Before we can do anything, we need to know * our hostname. */ gethostname(hostname, sizeof(hostname)); /* * Next, we need to look up the network * address of our host. */ if ((hp = gethostbyname(hostname)) == NULL) { fprintf(stderr, "%s: unknown host.\n", hostname); exit(1); } /* * Get a socket to work with. This socket will * be in the Internet domain, and will be a * stream socket. */ if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) { perror("client: socket"); exit(1); } /* * Create the address we will be connecting to. * We use port 1234 but put it into network * byte order. Also, we use bcopy (see Chapter * 14) to copy the network number. */ sin.sin_family = AF_INET; sin.sin_port = htons(1234); bcopy(hp->h_addr, &sin.sin_addr, hp->h_length); /* * Try to connect to the address. For this to * succeed, the server must already have bound * this address, and must have issued a listen() * request. */ if (connect(s, &sin, sizeof(sin)) < 0) { perror("client: connect"); exit(1); } /* * We'll use stdio for reading * the socket. */ fp = fdopen(s, "r"); /* * First we read some strings from the server * and print them out. */ for (i = 0; i < NSTRS; i++) { while ((c = fgetc(fp)) != EOF) { putchar(c); if (c == '\n') break; } } /* * Now we send some strings to the server. */ for (i = 0; i < NSTRS; i++) send(s, strs[i], strlen(strs[i]), 0); /* * We can simply use close() to terminate the * connection, since we're done with both sides. */ close(s); exit(0); }