IO::Lambda::DNS(3)

💅 IO::Lambda::DNS — DNS queries lambda style

Hi bestie! So this page is IO::Lambda::DNS(3) from the User Contributed Perl Documentation, and it's literally the glow-up your DNS lookups have been waiting for 🦋

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✨ NAME ✨

IO::Lambda::DNS — DNS queries, but lambda style. Iconic. No cap.

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🌸 DESCRIPTION 🌸

Okay so listen: this module gives you access to asynchronous DNS queries through Net::DNS. That's the whole vibe.

And because the author loves you, there are two functions that do the exact same operation — a constructor called new and a condition called dns. Pick whichever one matches your main character energy 💅

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🎀 SYNOPSIS 🎀

Here's the code, copy-pasted exactly because I would never do you dirty like that:

use strict;
use IO::Lambda::DNS qw(:all);
use IO::Lambda qw(:all);

# simple async query
my $reply = IO::Lambda::DNS-> new( "www.site.com" )-> wait;
print (($reply =~ /^\d/) ? "Resolved to $reply\n" : "Error: $reply\n");

# parallel async queries
lambda {
   for my $site ( map { "www.$_.com" } qw(google yahoo perl)) {
      context $site, 'MX', timeout => 0.25;
      dns { print shift-> string if ref($_[0]) }
   }
}-> wait;

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⭐ OPTIONS ⭐

The options that are specific to this module are:

• timeout or deadline — in seconds ⏱️
• retry — in times 🔁

Everything else — like nameservers, dnssec, etc etc (yes, the manpage literally says "etc etc", love that for us) — gets passed as is straight to the Net::DNS::Resolver constructor. So go read its man page for the details, bestie 🫶

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👑 USAGE 👑

💖 new — the constructor

Constructor new accepts Net::DNS-specific options (peep OPTIONS above, I got you) plus a query, and returns a lambda. That lambda takes no parameters, and gives you back either an IP address or a response object (depends on which call syntax you use, see below), or an error string.

new ($CLASS, %OPTIONS, $HOSTNAME) :: () -> ($IP_ADDRESS|$ERROR)

In the simple case, it takes a $HOSTNAME string and returns a string too — either an IP address or an error. To tell them apart, use the " /^\d/ " regexp. Why? Because it is guaranteed that no error message will begin with a digit, and no IP address will begin with anything other than a digit. Slay, honestly 🔥

new (%OPTIONS, ($PACKET | $HOSTNAME, $TYPE)) :: () -> ($RESPONSE|$ERROR)

In the complex case, it takes either a Net::DNS::Packet object, or a $HOSTNAME and $TYPE string — where that $TYPE can be one of A, MX, etc DNS query type. For the exact syntax, see "bgsend" in Net::DNS::Resolver.

It returns either a Net::DNS::RR object or an error string ✨

🦋 dns — condition wrapper over new

That's it. That's the whole thing. It's a condition wrapper over new:

dns (%OPTIONS, $HOSTNAME) -> $IP_ADDRESS|$ERROR
dns (%OPTIONS, ($PACKET | $HOSTNAME $TYPE)) -> $RESPONSE|$ERROR

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🌈 SEE ALSO 🌈

Go check out:

• IO::Lambda
• Net::DNS::Resolver

Both linked, both worth your time. Periodt 💜

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🌸 AUTHOR 🌸

Dmitry Karasik, <dmitry@karasik.eu.org>. Give him his flowers, he earned them 💐

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That's the whole page bestie, you're officially a DNS lambda girlie now 🧚

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Ok bye ily, this was perl v5.42.2 and the page itself is dated 2026-02-15 — the header up top says IO::Lambda::DNS(3), but you already knew that 💖