Len Len's personal site: work, cooking, cycling, experiences

The goal of this tinkering was simple: to parse a KML file for further interpretation and use using python and libxml2. (more…)

This is a very short example I managed to do in not a very long time which does the following things:

• opens an openoffice draw document
• modifies a field
• exports it as ps (using print to file)

Ah, and it does that from an external python program.

(more…)

The problem

Sometimes my evolution email client does the nasty thing that it duplicates some of the mails in my folders. I can think of 2 causes of this problem. Either it loses the track of mails downloaded from pop accounts on which the messages are not deleted imediately so it fetches them again or there is a problem with the filters that it forgets to delete the message from the original folder. This happens just once in a while but with folders containing thousands of mails some duplicates can be found. (more…)

The SOM (self organizing maps) are some very intuitive neural networks. There are a lot of more detailed description of these networks but here is a more intuitive description.

You have a number of neurons usually arranged in a 2D or 3D grid, each neuron has an associated weight vector. The input, which is a vector of the same size as the weight vector is connected to each neuron. The natural association is that each vector is a point in an n-dimensional space. By providing, during the learning phase, an uniformly distributed number of n-points to the network the neurons will arrange themself uniformly in the n-dimensions hypercube from which the n-points come from. Otherwise said, the neurons will classify the (sub)space, each neuron representing a partition of that (sub)space. When provided with a new point the network will act such that a single neuron will fire and that neuron will be the one closer to the provided sample. The network will classify the new point in an appropriate partition.

(more…)

#!/usr/bin/python

import sys, re

iE = '    '
pStart = re.compile('<[a-z]+',re.IGNORECASE)
pEnd = re.compile('(/>)|(</[a-z]+)', re.IGNORECASE)
pEndStartLine = re.compile('^\s*</[a-z]+', re.IGNORECASE)

def xmlIndent(fileName):
file = open(fileName, 'r')
out = ''
iCount = 0
while 1:
line = file.readline()
if not line: break
iEndAtStart = 0
line = line.lstrip()
if len(line) > 0:
if pEndStartLine.match(line):
iCount = iCount - 1
iEndAtStart = 1
line = mkIndent(iCount) + line
iCount = iCount + len(pStart.findall(line)) - len(pEnd.findall(line)) + iEndAtStart
#print iCount, '|%s|' % line
        out = out + line
file.close()
file = open(fileName, 'w')
file.write(out)
file.close()

def mkIndent(cnt):
out = ''
for t in range(0, cnt):
out += iE
return out

if __name__=='__main__':
xmlIndent(sys.argv[1])

#!/usr/local/bin/python

# $Id: knockd.py,v 1.5 2004/02/06 22:29:38 len Exp $

# Latest version can be found at http://nemesisit.rdsnet.ro/len

# Copyright (C) Marilen Corciovei <marilen.corciovei@nemesisit.ro>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.  This program is distributed in
# the hope that it will be useful, but WITHOUT ANY WARRANTY; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE.  See the GNU General Public License for more
# details; it is available at <http://www.fsf.org/copyleft/gpl.html>

""" knockd.py -- Demonstrate the portknock concept at server side """
""" FreeBSD with ipfw, python 2.2 """

import time, re, os, sys, math

""" Configs. CHANGE FOR YOUR CONFIGURATION """

log_filename =  '/var/log/ipfw.log'    #change this to your log location
ipfw = '/sbin/ipfw'                    #full path of ipfw program 
ifname = "my0"                         #interface name
mapsize = 10
ipdest = "10.10.10.23"                 #your ip 
openport = '22'                        #open this port
portseq = [4005, 40034, 9001]          #port sequence
tmdiff = 10                            #max 10s delay betwheen knocks

""" Global """
vis = {}

exp = "(\w\w\w\s{1,2}\d{1,2} \d\d:\d\d:\d\d) \w+ /kernel: ipfw: \d+ Deny \w+ (\d+\.\d+\.\d+\.\d+):(\d+) (\d+\.\d+\.\d+\.\d+):(\d+) in via " + ifname + "\s+" #change this to your format

p = re.compile(exp, re.IGNORECASE)

def daemonize():
""" Become a daemon"""
if os.fork(): os._exit(0)
os.setsid()
sys.stdin  = sys.__stdin__  = open('/dev/null','r')
sys.stdout = sys.__stdout__ = open('/dev/null','w')
sys.stdout = sys.__stderr__ = os.dup(sys.stdout.fileno())

def gatekeeper():
file = open(log_filename, 'r')
watcher = os.stat(log_filename)
this_modified = last_modified = watcher.st_mtime

file.seek(0,2)

while 1:
if this_modified > last_modified:
last_modified = this_modified
while 1:
line = file.readline()
if not line: break
parse_log(line)

watcher = os.stat(log_filename)
this_modified = watcher.st_mtime
time.sleep(1)

def do_something(ipfrom):
cmdparam = [ipfw,'add','2010','allow','tcp','from',ipfrom,'to',ipdest,openport,'setup']
os.spawnv(os.P_WAIT,ipfw,cmdparam)

def parse_log(line):
from time import strptime, strftime, mktime

if line.find('logfile turned over') != -1 and line.find('newsyslog') != -1:
print 'Restart daemon'
m = p.match(line)
if m:
when = m.group(1)
tm = mktime(strptime("2000 " + when, "%Y %b %d %H:%M:%S"))
#print strftime("%a, %d %b %Y %H:%M:%S +0000", tm)
                ipfrom = m.group(2)
portfrom = int(m.group(3))
ipdest = m.group(4)
portdest = int(m.group(5))
#print ipfrom, ipdest, portdest
                if vis.has_key(ipfrom):
ltm = vis[ipfrom][1]
if math.fabs(tm - ltm) < tmdiff: #accepted interval
lp = vis[ipfrom][0] #which port in sequence
if portseq[lp] == portdest:
if lp == len(portseq)-1: #last port found
print "Knock, knock from", ipfrom, "at", when
try:
do_something(ipfrom)
except:
print 'Could not open port'
del vis[ipfrom]
else:
vis[ipfrom] = [lp+1, tm]
else:
del vis[ipfrom]

elif portdest == portseq[0]:
vis[ipfrom] = [1,tm]

else:
print 'No match'

#clean the map for expired entries
        if len(vis) > mapsize:
print 'Cleaning map'
tm = mktime(strptime("2000 " + when, "%Y %b %d %H:%M:%S"))
for k, v in vis.items():
ltm = v[1]
if math.fabs(tm - ltm) > tmdiff: #expired
del vis[k]

if __name__=='__main__':
#daemonize()
        gatekeeper()

#!/usr/local/bin/python


# $Id: knock.py,v 1.2 2004/02/06 22:29:38 len Exp $

# Latest version can be found at http://nemesisit.rdsnet.ro/len

# Copyright (C) Marilen Corciovei <marilen.corciovei@nemesisit.ro>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.  This program is distributed in
# the hope that it will be useful, but WITHOUT ANY WARRANTY; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE.  See the GNU General Public License for more
# details; it is available at <http://www.fsf.org/copyleft/gpl.html>

""" knock.py -- Demonstrate the portknock concept at client side """

import socket, fcntl, os, sys
import select

""" Configs. CHANGE FOR YOUR CONFIGURATION """

ipdest = "10.10.10.23"                   #remote ip
portseq = [4005, 40034, 9001]            #port sequence
timeout = 3                              #timeout waiting for connection

def conn(sock, addr, dumbhack=None):

sock.setblocking(0)
try:
sock.connect(addr)
except socket.error:
pass

r,w,e = select.select([], [sock], [], timeout)
if w:
print 'socket open !?', addr
else:
print 'knock socket', addr

def knock_knock():

for port in portseq:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
conn(s, (ipdest, port))
s.close()

if __name__=='__main__':
knock_knock()