FM / examples

/usr/share/doc/python3-dns/examples

Name	Size	Mode	Actions
ddns.py	1204	0644	edit dl rm
e164.py	152	0644	edit dl rm
mx.py	225	0644	edit dl rm
name.py	468	0644	edit dl rm
reverse.py	1353	0644	edit dl rm
reverse_name.py	177	0644	edit dl rm
xfr.py	393	0644	edit dl rm
zonediff.py	11122	0644	edit dl rm

Edit: /usr/share/doc/python3-dns/examples/reverse.py (1353B)

#!/usr/bin/env python

# Usage: reverse.py <zone_filename>...
#
# This demo script will load in all of the zones specified by the
# filenames on the command line, find all the A RRs in them, and
# construct a reverse mapping table that maps each IP address used to
# the list of names mapping to that address.  The table is then sorted
# nicely and printed.
#
# Note!  The zone name is taken from the basename of the filename, so
# you must use filenames like "/wherever/you/like/dnspython.org" and
# not something like "/wherever/you/like/foo.db" (unless you're
# working with the ".db" GTLD, of course :)).
#
# If this weren't a demo script, there'd be a way of specifying the
# origin for each zone instead of constructing it from the filename.

from __future__ import print_function

import dns.zone
import dns.ipv4
import os.path
import sys

reverse_map = {}

for filename in sys.argv[1:]:
    zone = dns.zone.from_file(filename, os.path.basename(filename),
                              relativize=False)
    for (name, ttl, rdata) in zone.iterate_rdatas('A'):
        try:
            reverse_map[rdata.address].append(name.to_text())
        except KeyError:
            reverse_map[rdata.address] = [name.to_text()]

keys = reverse_map.keys()
keys.sort(key=dns.ipv4.inet_aton)
for k in keys:
    v = reverse_map[k]
    v.sort()
    print(k, v)

cmd: