AnyEvent::DNS::resolver

This function creates and returns a resolver that is ready to use and
should mimic the default resolver for your system as good as possible.
It is used by AnyEvent itself as well.

It only ever creates one resolver and returns this one on subsequent
calls
- see $AnyEvent::DNS::RESOLVER, below, for details.

Unless you have special needs, prefer this function over creating your
own resolver object.

The resolver is created with the following parameters:

 untaint          enabled
 max_outstanding  $ENV{PERL_ANYEVENT_MAX_OUTSTANDING_DNS} (default 10)

os_config will be used for OS-specific configuration, unless
$ENV{PERL_ANYEVENT_RESOLV_CONF} is specified, in which case that file
gets parsed.

$AnyEvent::DNS::RESOLVER

This variable stores the default resolver returned by
AnyEvent::DNS::resolver, or undef when the default resolver hasn't
been instantiated yet.

One can provide a custom resolver (e.g. one with caching
functionality) by storing it in this variable, causing all
subsequent resolves done via AnyEvent::DNS::resolver to be done
via the custom one.