Date: Thu, 29 Oct 2009 18:37:09 +0200 From: Giorgos Keramidas <keramida@ceid.upatras.gr> To: Martin McCormick <martin@dc.cis.okstate.edu> Cc: freebsd-questions@freebsd.org Subject: Re: Merging Related Information from 2 Tables Message-ID: <873a529mx6.fsf@kobe.laptop> In-Reply-To: <200910291539.n9TFcuKB078966@dc.cis.okstate.edu> (Martin McCormick's message of "Thu, 29 Oct 2009 10:38:56 -0500") References: <200910291539.n9TFcuKB078966@dc.cis.okstate.edu>
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On Thu, 29 Oct 2009 10:38:56 -0500, Martin McCormick <martin@dc.cis.okstate.edu> wrote:
> This is probably going to be a hashing exercise but I am checking to see
> if any of the building blocks needed are already out there.
>
> The problem is simple to describe in that there are 2 tables. One is a
> DNS zone transfer table of all the A or Address records in a given zone
> or from several zones for that matter. the other table is from the same
> zones and consists of text or TXT records. The only thing the 2 tables
> have in common is that some of the TXT records share the exact same name
> field as the A records so we should be able to display the important
> contents of the A and TXT records on the same line if their names match.
> The challenge is to do this quickly so some sort of hash function is
> needed to locate A and TXT records having the same name.
Hi Martin,
You should use a Perl or Python script, and a hash...
If you show us a few sample lines from the input file and how you want the
output to look, it shouldn't be too hard to quickly hack one of those
together.
With a short input file like this:
: keramida@kobe:/tmp$ cat input-file
: localhost IN A 127.0.0.1
: kobe IN A 127.0.0.1
: kobe IN TXT "This is a test"
You can construct a hash map of hostname -> list of records in
Python with a relatively short script:
: #!/usr/bin/env python
:
: import re
: import sys
:
: are = None # a regexp for matching 'A' records
: txtre = None # a regexp for matching 'TXT' records
:
: try:
: are = re.compile(r'^\s*(\S+)\s+[iI][nN]\s+[aA]\s+(((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)).*$')
: txtre = re.compile(r'^\s*(\S+)\s+[iI][nN]\s+[tT][xX][tT]\s+(.*)$')
: except Exception, inst:
: sys.stderr.write('regexp error: %s' % str(inst))
: sys.exit(1)
:
: hosts = {}
:
: for l in sys.stdin.readlines():
: l = l.rstrip('\n\r')
: # Is this an A record?
: m = are.match(l)
: if m:
: (name, addr) = (m.group(1), m.group(2))
: rec = ('A', addr)
: if not name in hosts:
: hosts[name] = [rec]
: else:
: hosts[name].append(rec)
: # Is this a TXT record?
: m = txtre.match(l)
: if m:
: (name, text) = (m.group(1), m.group(2))
: rec = ('TXT', text)
: if not name in hosts:
: hosts[name] = [rec]
: else:
: hosts[name].append(rec)
:
: print hosts
Running this script should produce something like:
: keramida@kobe:/tmp$ python martin.py < input-file
: {'kobe': [('A', '127.0.0.1'), ('TXT', '"This is a test"')],
: 'localhost': [('A', '127.0.0.1')]}
When you have the hash map of hostname to record-list for each host, you
can select and print any combination of host<=>record from this hash.
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