Question

So I’m trying to create a little script to deal with some logs. I’m just learning python, but know about loops and such in other languages. It seems that I don’t understand quite how the loops work in python.

I have a raw log from which I’m trying to isolate just the external IP addresses. An example line:

05/09/2011 17:00:18 192.168.111.26 192.168.111.255 Broadcast packet dropped udp/netbios-ns 0 0 X0 0 0 N/A

And heres the code I have so far:

import os,glob,fileinput,re

def parseips():
    f = open("126logs.txt",'rb')
    r = open("rawips.txt",'r+',os.O_NONBLOCK)

    for line in f:
        rf = open("rawips.txt",'r+',os.O_NONBLOCK)
        ip = line.split()[3]
        res=re.search('192.168.',ip)
        if not res:
            rf.flush()
            for line2 in rf:
                if ip not in line2:
                    r.write(ip+'\n')
                    print 'else write'
                else:
                    print "no"
    f.close()
    r.close()
    rf.close()  

parseips()

I have it parsing out the external ip’s just fine. But, thinking like a ninja, I thought how cool would it be to handle dupes? The idea or thought process was that I can check the file that the ips are being written to against the current line for a match, and if there is a match, don’t write. But this produces many more times the dupes than before 🙂 I could probably use something else, but I’m liking python and it makes me look busy.

Thanks for any insider info.

Answer 1

DISCLAIMER: Since you are new to python, I am going to try to show off a little, so you can lookup some interesting “python things”.

I’m going to print all the IPs to console:

def parseips():
    with open("126logs.txt",'r') as f:
        for line in f:
            ip = line.split()[3]
            if ip.startswith('192.168.'):
                print "%s\n" %ip, 

You might also want to look into:

f = open("126logs.txt",'r')
IPs = [line.split()[3] for line in f if line.split()[3].startswith('192.168.')]

Hope this helps,
Enjoy Python!