Sisimai::RFC1123(3pm)

💖 Sisimai::RFC1123(3pm) 💖

okay bestie, gather round, because this one is a little Perl class from the User Contributed Perl Documentation collection and it is, lowkey, exactly what you need when you're staring at a hostname and going "…is this valid or are you lying to me?" 🦋

It's called Sisimai::RFC1123 and no cap, it's all about Internet hosts. Let's get into it. 💅

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✨ NAME ✨

Sisimai::RFC1123 — the Internet hostname related class 🎀

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✨ SYNOPSIS ✨

Here's you, living your life, actually using it:

use Sisimai::RFC1123;

print Sisimai::RFC1123->is_internethost("mx2.example.jp"); # 1
print Sisimai::RFC1123->is_internethost("localhost");      # 0

See how "mx2.example.jp" said 1 (slay, valid) and "localhost" said 0 (not an Internet host, sorry girl)? That's the whole vibe. 👑

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✨ DESCRIPTION ✨

"Sisimai::RFC1123" is a class related to the Internet hosts. That's it, that's the description, it's giving focused. 💜

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✨ CLASS METHODS ✨

🌸 "is_internethost(String)"

The is_internethost() method returns true when the argument is a valid hostname. Literally that simple, no drama, main character energy only. ✨

print Sisimai::RFC1123->is_internethost("mx2.example.jp"); # 1
print Sisimai::RFC1123->is_internethost("localhost");      # 0

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🌸 "is_domainliteral(String)"

The is_domainliteral() method returns true when the domain part of the argument begins with "[IPv4:" or "[IPv6:" and is a valid domain literal. So if you're out here passing a bare IP without the little IPv4: / IPv6: tag, bestie, it's gonna say no. 🙈

print Sisimai::RFC1123->is_domainliteral("neko@[IPv4:192.0.2.1]);   # 1
print Sisimai::RFC1123->is_domainliteral("neko@[192.0.2.1]);        # 0

Two different results, two different vibes, IPv4: is doing all the heavy lifting. 🫶

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✨ AUTHOR ✨

azumakuniyuki 👑

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✨ COPYRIGHT ✨

Copyright (C) 2024-2026 azumakuniyuki, All rights reserved.

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✨ LICENSE ✨

This software is distributed under The BSD 2-Clause License. Go forth, use it responsibly, it's fr fr licensed. 🌈

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aaaand that's the page, bestie! 🎀 This was perl v5.40.1, dated 2026-07-05, coming to you from the Sisimai::RFC1123(3pm) manual. Hostname checks have never been this cute. Stay valid, stay iconic, mwah 💖💅