#!/usr/bin/env python3
import ipaddr
import os
import socket
import subprocess
import sys

def main():
    for arg in sys.argv[1:]:
        try:
            net = ipaddr.IPv4Network(arg)
        except ipaddr.AddressValueError:
            sys.stderr.write('Invalid network address: {}\n'.format(arg))
        else:
            for ip in net.iterhosts():
                p = subprocess.Popen(['ping', '-c1', '-W1', str(ip)],
                                     stdout=open(os.devnull, 'w'),
                                     stderr=open(os.devnull, 'w'),
                                     stdin=open(os.devnull))
                try:
                    p.wait()
                except KeyboardInterrupt:
                    print()
                    raise SystemExit
                try:
                    hostname = '{} ({})'.format(
                        ip,
                        socket.gethostbyaddr(str(ip))[0],
                    )
                except socket.herror:
                    hostname = ip
                state = 'in use' if p.returncode == 0 else 'not responding'
                print('{} is {}'.format(hostname, state))


if __name__ == '__main__':
    main()