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#--
#Copyright 2007 Nominet UK
#
#Licensed under the Apache License, Version 2.0 (the "License");
#you may not use this file except in compliance with the License.
#You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
#Unless required by applicable law or agreed to in writing, software
#distributed under the License is distributed on an "AS IS" BASIS,
#WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#See the License for the specific language governing permissions and
#limitations under the License.
#++
module Dnsruby
#== Dnsruby::Hosts class
#Dnsruby::Hosts is a hostname resolver that uses the system hosts file
#
#=== class methods
#* Dnsruby::Hosts.new(hosts='/etc/hosts')
#
#=== methods
#* Dnsruby::Hosts#getaddress(name)
#* Dnsruby::Hosts#getaddresses(name)
#* Dnsruby::Hosts#each_address(name) {|address| ...}
# address lookup methods.
#
#* Dnsruby::Hosts#getname(address)
#* Dnsruby::Hosts#getnames(address)
#* Dnsruby::Hosts#each_name(address) {|name| ...}
# hostnames lookup methods.
#
class Hosts
if /mswin32|cygwin|mingw|bccwin/ =~ RUBY_PLATFORM
require 'win32/resolv'
DefaultFileName = Win32::Resolv.get_hosts_path
else
DefaultFileName = '/etc/hosts'
end
#Creates a new Dnsruby::Hosts using +filename+ for its data source
def initialize(filename = DefaultFileName)
@filename = filename
@mutex = Mutex.new
@initialized = nil
end
def lazy_initialize# :nodoc:
@mutex.synchronize {
unless @initialized
@name2addr = {}
@addr2name = {}
begin
open(@filename) {|f|
f.each {|line|
line.sub!(/#.*/, '')
addr, hostname, *aliases = line.split(/\s+/)
next unless addr
addr.untaint
hostname.untaint
@addr2name[addr] = [] unless @addr2name.include? addr
@addr2name[addr] << hostname
@addr2name[addr] += aliases
@name2addr[hostname] = [] unless @name2addr.include? hostname
@name2addr[hostname] << addr
aliases.each {|n|
n.untaint
@name2addr[n] = [] unless @name2addr.include? n
@name2addr[n] << addr
}
}
}
rescue Exception
# Java won't find this file if running on Windows
end
@name2addr.each {|name, arr| arr.reverse!}
@initialized = true
end
}
self
end
#Gets the first IP address for +name+ from the hosts file
def getaddress(name)
each_address(name) {|address| return address}
raise ResolvError.new("#{@filename} has no name: #{name}")
end
#Gets all IP addresses for +name+ from the hosts file
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
end
#Iterates over all IP addresses for +name+ retrieved from the hosts file
def each_address(name, &proc)
lazy_initialize
if @name2addr.include?(name)
@name2addr[name].each(&proc)
end
end
#Gets the first hostname of +address+ from the hosts file
def getname(address)
each_name(address) {|name| return name}
raise ResolvError.new("#{@filename} has no address: #{address}")
end
#Gets all hostnames for +address+ from the hosts file
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
end
#Iterates over all hostnames for +address+ retrieved from the hosts file
def each_name(address, &proc)
lazy_initialize
if @addr2name.include?(address)
@addr2name[address].each(&proc)
end
end
end
end
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