Install whois with Homebrew, apk, chocolatey, apt, dnf, MacPorts, Nix, pacman, winget, zypper

Project links

• Homepage
• Upstream docs
• Package manager page

Commands and aliases

• whois

Project history

The WHOIS protocol predates the modern commercial Internet. RFC 812 described NICNAME/WHOIS in 1982 as an ARPANET directory service running at the Network Information Center at SRI International; RFC 954 updated the official NICNAME/WHOIS specification in 1985; RFC 3912 replaced those earlier RFCs in September 2004 with the current WHOIS protocol specification.

Marco d'Itri's client has its own narrower software history. The README says he wrote this Whois client from scratch in 1999 because alternatives were obsolete or bloated. The client is described as intelligent because it automatically selects the appropriate WHOIS server for most queries, with an internal database that is often more accurate than IANA's published data.

The rfc1036/whois GitHub repository was created on March 31, 2013, but the canonical release distribution remains Debian's source pool. The README also explains the historically odd inclusion of `mkpasswd`, a password-hash helper inherited from the original RIPE whois package lineage.

Adoption history

WHOIS became a default operational lookup mechanism for domain registrations, IP network assignments, autonomous system numbers, and registry contacts. IANA's WHOIS service still exposes a port 43 service and accepts domain names, IP addresses, and AS numbers, while ICANN operates a registration-data lookup service for public domain and Internet number resource data.

The rfc1036 client became especially visible through Debian and derivative distributions. Debian describes the package as an intelligent WHOIS client for RFC 3912 queries, and package indexes across Unix-like systems package the same code because it solves the mundane but persistent problem of knowing which registry server to ask.

WHOIS has also acquired historical baggage: free-form text responses, inconsistent formats, privacy restrictions, and the later emergence of RDAP as a more structured successor. That context makes the command-line client useful but also explains why serious automation often needs registry-specific parsing or newer protocols.

How it is used

Typical usage is a direct terminal lookup such as `whois example.com`, an IP address, an AS number, or a registry handle. The client chooses a server, sends a simple text query over the WHOIS protocol, and prints the human-readable registry response.

Network operators, security researchers, abuse desks, domain buyers, and developers use `whois` for quick ownership, delegation, registrar, nameserver, allocation, and contact clues. The result is intentionally close to the registry's original text output, which is convenient for humans but uneven for scripts.

Why package nerds care

whois is package-nerd infrastructure in the oldest sense: a small command that turns Internet registry bureaucracy into a shell query. It is the kind of tool that persists because every generation of network debugging still needs to ask who owns a name, address block, or ASN.

The rfc1036 implementation is notable because it adds registry-selection intelligence to an intentionally minimal protocol. The package also carries the strange Unix fossil `mkpasswd`, a reminder that package histories often preserve useful leftovers from older network-operations toolchains.

Timeline

• 1982: RFC 812 described NICNAME/WHOIS for ARPANET directory lookups.
• 1985: RFC 954 updated NICNAME/WHOIS and became the official protocol specification.
• 1999: Marco d'Itri wrote a new Whois client from scratch because alternatives were obsolete or bloated.
• 2004-09: RFC 3912 standardized the current WHOIS protocol specification and obsoleted RFC 954 and RFC 812.
• 2013-03-31: The rfc1036/whois GitHub repository was created.
• 2026-07-02: The project remained packaged across Unix-like package ecosystems and maintained as Debian-oriented source.

Related projects

• IANA WHOIS is a central referral-style WHOIS service for domains, IP addresses, and AS numbers.
• ICANN Lookup is a web-facing registration data lookup service.
• RDAP is the structured, HTTP-based successor protocol often discussed as a replacement for free-form WHOIS responses.
• RIPE whois is part of the older client lineage referenced by the package's `mkpasswd` history.

Sources

• Debian package description: https://packages.debian.org/sid/whois
• Debian package tracker: https://tracker.debian.org/whois
• IANA WHOIS service: https://www.iana.org/whois
• ICANN WHOIS/RDDS page: https://www.icann.org/resources/pages/whois-rdds-2023-11-02-en
• RFC 3912 WHOIS Protocol Specification: https://datatracker.ietf.org/doc/rfc3912/
• RFC 812 NICNAME/WHOIS: https://www.rfc-editor.org/info/rfc812
• RFC 954 NICNAME/WHOIS: https://www.rfc-editor.org/info/rfc954
• rfc1036/whois GitHub API metadata: https://api.github.com/repos/rfc1036/whois
• rfc1036/whois repository and README: https://github.com/rfc1036/whois