#!/usr/bin/env python3

import ipaddress
import socket
import sys

if len(sys.argv) != 2:
    raise SystemExit(f"Usage: {sys.argv[0]} <ip-address>")

try:
    address = str(ipaddress.ip_address(sys.argv[1]))
except ValueError as exc:
    raise SystemExit(f"Invalid IP address: {exc}")

try:
    hostname, aliases, addresses = socket.gethostbyaddr(address)
except socket.herror as exc:
    raise SystemExit(f"No reverse DNS hostname found for {address}: {exc}")

print(f"IP address: {address}")
print(f"Primary hostname: {hostname}")

if aliases:
    print("Aliases:")
    for alias in aliases:
        print(f"  {alias}")

print("Resolved addresses:")
for resolved in addresses:
    print(f"  {resolved}")