This library provides an asynchronous DNS resolver on top
of GNU ADNS http://www.chiark.greenend.org.uk/~ian/adns/.
Not all options are supported, but A, MX, and PTR lookups
work nicely. There is also support for retrieving generic
RR types, CNAMEs, and for NSEC zone walking. The library
can be expected to work with fine ADNS 1.4 or later. It
might also work with version ADNS 1.3, but that hasn't
been tested.
The example program adns-reverse-lookup.hs demonstrates
how the resolver is used. Given a list of host names on
the command line, it performs an A/PTR double-lookup and
checks whether the records are consistent. The
output is printed in the order in which the DNS responses
arrive: