`class Hosts`

An interface for querying the system's hosts file.

Definitions

`def self.local`

Hosts for the local system.

Implementation

def self.local
	hosts = self.new
	
	path = System.hosts_path
	
	if path and File.exist?(path)
		File.open(path) do |file|
			hosts.parse_hosts(file)
		end
	end
	
	return hosts
end

`def initialize`

Create a new hosts file interface.

Implementation

def initialize
	@addresses = {}
	@names = {}
end

`def lookup(name, origin: nil)`

Lookup a name in the hosts file.

Implementation

def lookup(name, origin: nil)
	name = Resolv::DNS::Name.create(name).with_origin(origin)
	
	addresses = @names[name]
	
	if addresses
		addresses.last
	else
		nil
	end
end

`def add(address, names)`

Add a new address with the given names.

Implementation

def add(address, names)
	@addresses[address] ||= []
	@addresses[address] += names
	
	names.each do |name|
		name = Resolv::DNS::Name.create(name).with_origin(nil)
		
		@names[name] ||= []
		@names[name] << address
	end
end

`def parse_hosts(io)`

Parse a hosts file and add the entries.

Implementation

def parse_hosts(io)
	io.each do |line|
		line.sub!(/#.*/, "")
		address, hostname, *aliases = line.split(/\s+/)
		
		if address =~ Resolv::IPv4::Regex
			address = Resolv::IPv4.create(address)
		elsif address =~ Resolv::IPv6::Regex
			address = Resolv::IPv6.create(address)
		else
			next
		end
		
		add(address, [hostname] + aliases)
	end
end