linkchecker/DNS/lazy.py

# $Id$
# routines for lazy people.
import Base

def revlookup(name): 
    "convenience routine for doing a reverse lookup of an address"
    a = name.split('.')
    a.reverse()  
    b = '.'.join(a)+'.in-addr.arpa'
    # this will only return one of any records returned.
    return Base.DnsRequest(b, qtype = 'ptr').req().answers[0]['data']

def mxlookup(name, protocol="tcp"):
    """
    convenience routine for doing an MX lookup of a name. returns a
    sorted list of (preference, mail exchanger) records
    """
    a = Base.DnsRequest(name, qtype='mx', protocol=protocol).req().answers
    l = map(lambda x:x['data'], a)
    l.sort()
    return l