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
NIS is not supported.
/etc/nsswitch.conf is not supported.
# File lib/resolv.rb, line 57 def self.each_address(name, &block) DefaultResolver.each_address(name, &block) end
Iterates over all IP addresses for name.
# File lib/resolv.rb, line 78 def self.each_name(address, &proc) DefaultResolver.each_name(address, &proc) end
Iterates over all hostnames for address.
# File lib/resolv.rb, line 43 def self.getaddress(name) DefaultResolver.getaddress(name) end
Looks up the first IP address for name.
# File lib/resolv.rb, line 50 def self.getaddresses(name) DefaultResolver.getaddresses(name) end
Looks up all IP address for name.
# File lib/resolv.rb, line 64 def self.getname(address) DefaultResolver.getname(address) end
Looks up the hostname of address.
# File lib/resolv.rb, line 71 def self.getnames(address) DefaultResolver.getnames(address) end
Looks up all hostnames for address.
# File lib/resolv.rb, line 89
def initialize(resolvers=(arg_not_set = true; nil), use_ipv6: (keyword_not_set = true; nil))
if !keyword_not_set && !arg_not_set
warn "Support for separate use_ipv6 keyword is deprecated, as it is ignored if an argument is provided. Do not provide a positional argument if using the use_ipv6 keyword argument.", uplevel: 1
end
@resolvers = case resolvers
when Hash, nil
[Hosts.new, DNS.new(DNS::Config.default_config_hash.merge(resolvers || {}))]
else
resolvers
end
end # File lib/resolv.rb, line 122
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 lib/resolv.rb, line 157
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 lib/resolv.rb, line 105
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 lib/resolv.rb, line 113
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
end Looks up all IP address for name.
# File lib/resolv.rb, line 140
def getname(address)
each_name(address) {|name| return name}
raise ResolvError.new("no name for #{address}")
end Looks up the hostname of address.
# File lib/resolv.rb, line 148
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
end Looks up all hostnames for address.
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Licensed under the Ruby License.
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Licensed under their own licenses.