if (! host_lookup) { return NULL; }
char *host2ip(char *host) {	struct hostent *hp;	struct sockaddr_in addr;	char *str;	hp = gethostbyname(host);	if (!hp) {		return NULL;	}	memset(&addr, 0, sizeof(addr));	addr.sin_family = AF_INET;	addr.sin_addr.s_addr =  *(unsigned long *)hp->h_addr;	str = strdup(inet_ntoa(addr.sin_addr));	return str;}