Module: DomainPrefix

Extended by:
DomainPrefix
Included in:
DomainPrefix
Defined in:
lib/domain_prefix.rb

Defined Under Namespace

Classes: Tree

Constant Summary collapse

SEPARATOR = 
'.'.freeze
TLDIFIER_SOURCE_FILE = 
File.expand_path(File.join('..', 'data', 'effective_tld_names.dat'), File.dirname(__FILE__))
TLD_SET = 
begin
  File.open(TLDIFIER_SOURCE_FILE, 'r:UTF-8') do |f|
    f.read.split(/\n/).collect do |line|
      line.sub(%r[//.*], '').sub(/\s+$/, '')
    end.reject(&:empty?).freeze
  end
end
TLD_NAMES = 
TLD_SET.sort_by do |d|
  [ -d.length, d ]
end.freeze
TLD_TREE = 
TLD_NAMES.inject(Tree.new) do |t, name|
  t.insert(name)
end.freeze
NONPUBLIC_TLD = 
{
  'local' => true
}.freeze

Instance Method Summary collapse

Instance Method Details

#name(fqdn) ⇒ Object

Returns the name component of a given domain or nil if one cannot be determined.



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# File 'lib/domain_prefix.rb', line 99

def name(fqdn)
  if (fqdn = registered_domain(fqdn))
    fqdn.split(SEPARATOR).first
  else
    nil
  end
end

#public_suffix(domain) ⇒ Object

Returns the public suffix (e.g. “co.uk”) for a given domain or nil if one cannot be determined.



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# File 'lib/domain_prefix.rb', line 71

def public_suffix(domain)
  return unless (domain)

  components = rfc3492_canonical_domain(domain).split(SEPARATOR)

  return if (components.empty? or components.find(&:empty?))

  return unless (public_tld?(components.last))

  suffix = TLD_TREE.follow(components)
  
  return unless (suffix)

  suffix.shift

  suffix.join(SEPARATOR)
end

#public_tld?(tld) ⇒ Boolean

Returns true if the given tld is listed as public, false otherwise.



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# File 'lib/domain_prefix.rb', line 39

def public_tld?(tld)
  !NONPUBLIC_TLD.key?(tld)
end

#registered_domain(fqdn, rules = :strict) ⇒ Object

Returns the registered domain name for a given FQDN or nil if one cannot be determined.



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# File 'lib/domain_prefix.rb', line 45

def registered_domain(fqdn, rules = :strict)
  return unless (fqdn)
  
  components = rfc3492_canonical_domain(fqdn).split(SEPARATOR)
  
  return if (components.empty? or components.find(&:empty?))

  if (rules == :strict)
    return unless (self.public_tld?(components.last))
  end

  suffix = TLD_TREE.follow(components)

  unless (suffix)
    if (rules == :relaxed and components.length >= 2 and !TLD_TREE[components[-1]])
      return components.last(2).join(SEPARATOR)
    else
      return
    end
  end
  
  suffix.join(SEPARATOR)
end

#rfc3492_canonical_domain(domain) ⇒ Object

Returns a cleaned up, canonical version of a domain name.



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# File 'lib/domain_prefix.rb', line 32

def rfc3492_canonical_domain(domain)
  # FIX: Full implementation of RFC3429 required.
  # http://www.ietf.org/rfc/rfc3492.txt
  domain and domain.downcase
end

#tld(fqdn) ⇒ Object

Returns the very top-level domain for a given domain, or nil if one cannot be determined.



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# File 'lib/domain_prefix.rb', line 91

def tld(fqdn)
  suffix = public_suffix(rfc3492_canonical_domain(fqdn))
  
  suffix and suffix.split(SEPARATOR).last
end