[root@bogon dns]# vim CNAME.py
!/usr/bin/env python
import dns.resolver
domain = raw_input('Please input an domain: ')
cname = dns.resolver.query(domain, 'CNAME')
for i in cname.response.answer:
for j in i.items:
print j.to_text()
测试：
[root@bogon dns]# python CNAME.py
Please input an domain: www.baidu.com
www.a.shifen.com.
[root@bogon dns]#
