idn

First things first: I'm storing multiple domains to a database, after I've converted each and every domain name to it's IDNA version. What I need to know the maximum length such an IDNA-converted domain name can have so I can define the database field's max length. Known fact: Now, I know the maximum number of characters in a domain name (including any subdomains) is 255 characters. Where I lost it: That's easy at first glance, but... does this mean regular ascii characters of international characters (think UTF-8 encoding)? To give you an example: The domain "müller.de" has 9 characters when

Some people will reply that domain names are not case-sensitive. In the new Unicode world this is no longer true. ( Source ) I thought one of the steps in the Unicode > Punycode conversion was a "normalisation", which rendered domain names lower case. For old-fashioned ASCII -based domain names , Yes, domain names have been and continue to be case-insensitive. For example, all of these represent the same domain: example.com Example.com EXAMPLE.COM EXampLE.com In modern DNS , we now have Internationalized Domain Names (IDN) which allows Unicode characters. The problem is that defining upper-

I'm writing a Rails app that needs to convert an IDN domain name from Punycode into its Unicode equivalent. I tried installing the idn gem that has bindings to GNU LibIDN, but it won't compile the native code. Apparently others have the same issue with Ruby 1.9.x. I also tried the pure Ruby SimpleIDN gem , but I would prefer something native. Leo Grove Try the simpleidn gem . It works with Ruby 1.8.7 and 1.9.2. Edit your Gemfile: gem 'simpleidn' then you can enter the command as follows: SimpleIDN.to_unicode("xn--mllerriis-l8a.com") => "møllerriis.com" SimpleIDN.to_ascii("møllerriis.com") =>

What is the best way to convert an internationalized domain name to its ASCII-form? I want to convert Bücher.ch into xn--bcher-kva.ch by using some sort of (free) .net code. Have a look at the GNU IDN Library - Libidn . The introduction says that C# libraries are available. adam using System.Globalization; ... IdnMapping idn = new IdnMapping(); MessageBox.Show(idn.GetAscii("www.kraków.pl")); To Get the other way around from xn--bcher-kva.ch domain to Bücher.ch using System.Globalization; ... IdnMapping idn = new IdnMapping(); MessageBox.Show(idn.GetUnicode("xn--bcher-kva.ch")); You will get

I need help building a regular expression that can properly match an URL inside free text. scheme One of the following: ftp , http , https (is ftps a protocol?) optional user (and optional pass ) host (with support for IDNs) support for www and sub-domain(s) (with support for IDNs) basic filtering of TLDs ( [a-zA-Z]{2,6} is enough I think) optional port number path (optional, with support for Unicode chars) query (optional, with support for Unicode chars) fragment (optional, with support for Unicode chars) Here is what I could find out about sub-domains: A "subdomain" expresses relative