addr

        # IPSocket.addr

(from ruby core)
---
    ipsocket.addr([reverse_lookup]) => [address_family, port, hostname, numeric_address]

---

Returns the local address as an array which contains address_family,
port, hostname and numeric_address.

If `reverse_lookup` is `true` or `:hostname`, hostname is obtained from
numeric_address using reverse lookup. Or if it is `false`, or
`:numeric`, hostname is the same as numeric_address. Or if it is `nil`
or omitted, obeys to `ipsocket.do_not_reverse_lookup`. See
`Socket.getaddrinfo` also.

    TCPSocket.open("www.ruby-lang.org", 80) {|sock|
      p sock.addr #=> ["AF_INET", 49429, "hal", "192.168.0.128"]
      p sock.addr(true)  #=> ["AF_INET", 49429, "hal", "192.168.0.128"]
      p sock.addr(false) #=> ["AF_INET", 49429, "192.168.0.128", "192.168.0.128"]
      p sock.addr(:hostname)  #=> ["AF_INET", 49429, "hal", "192.168.0.128"]
      p sock.addr(:numeric)   #=> ["AF_INET", 49429, "192.168.0.128", "192.168.0.128"]
    }