dnslookup — A simple Ruby CLI tool for querying DNS records

dnslookup is a Ruby CLI for querying A, MX, CNAME, and TXT records from default or custom DNS servers. It wraps dig with a small command-line interface that is useful for quick troubleshooting, scripting, and day-to-day DNS checks.

Please use GitHub Issues to report bugs.

• Ruby 3.0 or newer
• The dig executable available on your PATH

If dig is not already installed, common package names are:

brew install bind

sudo apt-get install dnsutils

To add dnslookup to an existing project, add this line to your project's Gemfile:

gem 'dnslookup'

And then execute:

bundle install

Or to install the CLI locally:

gem install dnslookup

Lookup DNS records for a domain:

dnslookup example.com -a

If you omit a record-type option, dnslookup queries A records by default:

dnslookup example.com

By default, dnslookup queries Google's public resolvers: 8.8.8.8 and 8.8.4.4. Use -s to query a specific resolver.

Lookup the default A record:

dnslookup example.com

Lookup a CNAME record explicitly:

dnslookup ftp.victorkeenan.com -c

Query a specific name server:

dnslookup example.com -a -s1.1.1.1

Query all supported record types at once:

dnslookup example.com --all

If dig cannot complete the lookup, dnslookup reports the query as failed instead of showing an empty result:

dnslookup example.com -a -s203.0.113.53

Depending on the failure, the output will include either (query failed) or (query failed: ...).

Help with usage and options:

dnslookup -h

Bug reports and pull requests are welcome on GitHub. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the terms specified in the CODE OF CONDUCT.

dnslookup is copyright © 2016-2026 Victor S. Keenan. It is free software and may be redistributed under the terms specified in the LICENSE file.

Code crafted by me, Victor S. Keenan. Find me on Twitter @VictorSK or hire me to design, develop, and grow your product or service.