+/* Look up HOST in DNS and return a list of IP addresses.
+
+ This function caches its result so that, if the same host is passed
+ the second time, the addresses are returned without the DNS lookup.
+ If you want to force lookup, call forget_host_lookup() prior to
+ this function, or set opt.dns_cache to 0 to globally disable
+ caching.
+
+ FLAGS can be a combination of:
+ LH_SILENT - don't print the "resolving ... done" message.
+ LH_IPV4_ONLY - return only IPv4 addresses.
+ LH_IPV6_ONLY - return only IPv6 addresses. */
+