lookup-hostname

Arguments: host &key ignore-cache ipv6 all

host should be a string naming a host, a 32-bit IP address, a string in dotted form, or an IPv6 address. This function returns the 32-bit IP address or an IPv6 address structure for the host. An error is signaled if the host can not be found. See the documentation for *dns-mode* for information on the manner in which name resolution occurs.

To enhance performance, lookup-hostname caches answers to queries and reuses those answers for subsequent lookups of the same name. If the IP address associated with a given hostname has changed since the information was cached, lookup-hostname may return out-of-date information.

If the ignore-cache argument is specified true, then the lookup will be done by querying the operating system libraries rather than using a value that Lisp has cached. The result of the lookup is still cached, however.

The ipv6 keyword argument was added with IPv6 support. ipv6 defaults to the value of *ipv6*. If nil, only IPv4 addresses will be returned. If :ipv6, then only IPv6 addresses will be returned. If t, then IPv6 addresses (if any) are returned in preference of IPv4 addresses. If ipv6 and all are both t, IPv6 addresses will be before IPv4 addresses in the returned list.

The all keyword argument was added with IPv6 support. If all is true, this function will return a list of all records.

See also *dns-mode*.

See socket.htm for general information on sockets in Allegro CL.

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This page was not revised from the 10.0 page.
Created 2019.8.20.