Resolv is a thread-aware DNS resolver library written in Ruby. Resolv can handle multiple DNS requests concurrently without blocking the entire Ruby interpreter.
See also resolv-replace.rb to replace the libc resolver with Resolv.
Resolv can look up various DNS resources using the DNS module directly.
Examples:
p Resolv.getaddress "www.ruby-lang.org" p Resolv.getname "210.251.121.214" Resolv::DNS.open do |dns| ress = dns.getresources "www.ruby-lang.org", Resolv::DNS::Resource::IN::A p ress.map(&:address) ress = dns.getresources "ruby-lang.org", Resolv::DNS::Resource::IN::MX p ress.map { |r| [r.exchange.to_s, r.preference] } end
Bugs
-
NIS is not supported.
-
/etc/nsswitch.conf is not supported.
Default resolver to use for Resolv class methods.
Address Regexp to use for matching IP addresses.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 59
def self.each_address(name, &block)
DefaultResolver.each_address(name, &block)
end
Iterates over all IP addresses for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 80
def self.each_name(address, &proc)
DefaultResolver.each_name(address, &proc)
end
Iterates over all hostnames for address.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 45
def self.getaddress(name)
DefaultResolver.getaddress(name)
end
Looks up the first IP address for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 52
def self.getaddresses(name)
DefaultResolver.getaddresses(name)
end
Looks up all IP address for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 66
def self.getname(address)
DefaultResolver.getname(address)
end
Looks up the hostname of address.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 73
def self.getnames(address)
DefaultResolver.getnames(address)
end
Looks up all hostnames for address.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 87
def initialize(resolvers=nil, use_ipv6: nil)
@resolvers = resolvers || [Hosts.new, DNS.new(DNS::Config.default_config_hash.merge(use_ipv6: use_ipv6))]
end
Creates a new Resolv using resolvers.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 111
def each_address(name)
if AddressRegex =~ name
yield name
return
end
yielded = false
@resolvers.each {|r|
r.each_address(name) {|address|
yield address.to_s
yielded = true
}
return if yielded
}
end
Iterates over all IP addresses for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 146
def each_name(address)
yielded = false
@resolvers.each {|r|
r.each_name(address) {|name|
yield name.to_s
yielded = true
}
return if yielded
}
end
Iterates over all hostnames for address.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 94
def getaddress(name)
each_address(name) {|address| return address}
raise ResolvError.new("no address for #{name}")
end
Looks up the first IP address for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 102
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
end
Looks up all IP address for name.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 129
def getname(address)
each_name(address) {|name| return name}
raise ResolvError.new("no name for #{address}")
end
Looks up the hostname of address.
# File tmp/rubies/ruby-3.3.0/lib/resolv.rb, line 137
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
end
Looks up all hostnames for address.