nslookup
A {Unix} utility by Andrew Cherenson for querying {Internet}
{domain name server}s. The basic use is to find the {Internet
address} corresponding to a given {hostname} (or vice versa).
By changing the query type (e.g. "set type◦CNAME") other types
of information can be obtained including CNAME - the
{canonical name} for an alias; HINFO - the host {CPU} and
{operating system} type; MINFO - mailbox or mail list
information; {MX} - {mail exchanger} information; NS - the
{name server} for the named zone; PTR - the hostname if the
query is an Internet address, otherwise the pointer to other
information; SOA the domain's start-of-authority information;
TXT - text information; UINFO - user information; WKS -
supported {well-known service}s. Other types (ANY, AXFR, MB,
MD, MF, NULL) are described in {RFC 1035}.
{(ftp://src.doc.ic.ac.uk/computing/operating-systems/unix/bsd-sources/u