#!/usr/bin/perl -w
use strict;
use warnings;
use AnyEvent::DNS;

my ($domain);
my (@domains,@condvars);

my $resolver = AnyEvent::DNS::resolver;

while ($domain = <>;)
{
  # clean off newline
  chomp $domain;
  
  # send dns packets
  $resolver->resolve($domain,"*",my $condvar  = AnyEvent->condvar);

  # receive dns packets
  $condvar->recv;
  print "$domain\n";
}
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#!/usr/bin/perl -w
use strict;
use warnings;
use AnyEvent::DNS;

my ($domain);
my (@domains,@condvars);

my $resolver = AnyEvent::DNS::resolver;

while (1)
{
  # send dns packets
  for my $i (1..10)
  {
    $domain = <>;
    # clean off newline
    chomp $domain;
    $resolver->resolve($domain,"*",my $condvar  = AnyEvent->condvar);
    push @condvars, $condvar; 
  }
  
  # receive dns packets
  while (my $condvar = pop @condvars)
  {
    $condvar->recv;
    print "$domain\n";
  }
}
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You get ten times the "one domain", because you print $domain 10 times. What value would you $domain to have at which time?

Looking at the documentation of AnyEvent::DNS, the SYNOPSIS section shows how to retrieve results from a query. I'm not sure what problems you have with that.

If you want to do a callback-driven approach, take a look at the AnyEvent::DNS::srv subroutine. Again, the usage seems quite straightforward, as the resolved IPs get passed as parameters.

Thanks, in the meantime I'd realised that myself. Just in case it's useful to anybody else I include my code so far for asynchronous resolution. As far as I can see from the documentation retrieving records from the results should be as simple as traversing an array of arrays and picking out the bits you want. e.g. A or AAAA records.

#!/usr/bin/perl -w
use strict;
use warnings;
use Data::Dumper;
use AnyEvent::DNS;

my ($domain,$START_TIME,$MAX_QUERIES,$MAX_QUEUE,
    $time,$done,$resolved);
my (@domains,@condvars);

$START_TIME = time;
$MAX_QUERIES = 1000;
$MAX_QUEUE   = 10;
$resolved = 0;

# setup resolver
my $resolver = AnyEvent::DNS::resolver;
$resolver->max_outstanding($MAX_QUEUE);
#$resolver->timeout([0,1,2]);

while (1)
{
  # send dns packets
  for my $i (1..$MAX_QUERIES)
  {
    $domain = <>;
    # clean off newline
    chomp $domain;
    $resolver->resolve($domain,"*",my $condvar  = AnyEvent->condvar);
    push @condvars, $condvar; 
  }
  
  # receive dns packets
  while (my $condvar = pop @condvars)
  {
    $resolved++ if ($condvar->recv);
    #warn Dumper [$condvar->recv];
  }
  $done += $MAX_QUERIES;
  $time = time - $START_TIME;
  print "Done $done domains, $resolved resolved in $time seconds.\n";
}
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Following is the most simple usage example from the AnyEvent::HTTP documentation. For me this program finishes without any output. Does anybody have any ideas why this doesn't work?

#!/usr/bin/perl -w
use strict;
use warnings;
use AnyEvent::HTTP;

http_get "http://www.google.com/", sub { print $_[1] };
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