4.1cBSD/usr/src/new/courier/lib/foo

static
CourierActivate(program_name, host)
	String program_name, host;
{
	struct hostent *hp;
	struct servent *srvp;
	int f;
	struct sockaddr_in sin;
	Unspecified buf[50];
	Cardinal n;
	char c;

	hp = gethostbyname(host);
	if (hp == 0) {
		fprintf(stderr, "%s: unknown host\n", host);
		return (-1);
	}
	srvp = getservbyname("courier", "tcp");
	if (srvp == 0) {
		fprintf(stderr, "tcp/courier: unknown service\n");
		return (-1);
	}
	f = socket(AF_INET, SOCK_STREAM, 0, 0);
	if (f < 0) {
		if (errno != EMFILE)
			perror("socket");
		return (-1);
	}
	sin.sin_family = AF_INET;
	sin.sin_port = 0;
	sin.sin_addr.s_addr = 0;
	if (bind(f, (caddr_t)&sin, sizeof (sin), 0) < 0) {
		perror("bind");
		goto bad;
	}
	sin.sin_family = hp->h_addrtype;
	sin.sin_addr = *(struct in_addr *) hp->h_addr;
	sin.sin_port = srvp->s_port;
	if (connect(f, (caddr_t)&sin, sizeof(sin), 0) < 0) {
		perror(hp->h_name);
		goto bad;
	}
#if DEBUG
	if (CourierClientDebuggingFlag)
		fprintf(stderr, "[CourierActivate: connected to %s]\n", hp->h_name);
#endif
	n = PackString(&program_name, buf, 1);
	write(f, buf, n*sizeof(Unspecified));
	if (read(f, &c, 1) != 1) {
		perror(host);
		goto bad;
	}
	if (c != 0) {
		do write(fileno(stderr), &c, 1);
		while (read(f, &c, 1) == 1 && c != 0);
		goto bad;
	}
#if DEBUG
	if (CourierClientDebuggingFlag)
		fprintf(stderr, "[CourierActivate: running %s]\n", program_name);
#endif
	return (f);
bad:
	close(f);
	return (-1);
}