Hi,

First post to these forums.

Basically i need to take a file, sort it, then extract different patterns in it.

The data is IP addresses and i want to split it up by Subnet.

I.e. sample data hosts.log (made up)

1.0.0.1
1.0.0.2
1.0.0.3
1.0.1.4
1.0.1.5
1.0.1.6
1.0.2.7
1.0.2.8
1.0.2.9
(etc.etc.....)
9.1.1.1
9.1.2.2
(etc.etc.....)

Then split into

1.0.0.log ::
1.0.0.1
1.0.0.2
1.0.0.3

1.0.1.log ::
1.0.1.4
1.0.1.5
1.0.1.6

Is this possible or alot of scripting? I dont mind how the output is renamed, but if it was by subnet's that would be great.

I have had a look at Awk, Sed etc. etc. and have not been able to find anything that matches what i want to do.

My apologies if this is a little OTT! :-)

Try this :

Fantastic thank you.

Now my next task is actually understanding how that just happened..

:-)

sort -t. -n -k1,4 ip.txt|
Sort the input file
-t. field delimiter = '.'
-n numeric sort
-k1,4 sort fields 1, 2 3 4

awk '{ ... }'
Proceed each line from result of sort.

subnet = $1;
sub(/\.[^.]*$/,"",subnet)
determine the subnet by removing last '.' and all chars after, from the ip addr ($1)

if (subnet != subnet_prv)
Test if the subnet is the same as the previous.

if (! prv_subnet) close(subnet_file);
subnet_file = subnet ".log";
print $1 > subnet_file;
Then clause. The subnet is different from previous.
If an output file is already open (for previous subnet), close it.
The new output filename is "subnet".log
The ip add is written to the outfile which is created

print $1 >> subnet_file;
Else clause. The subnet is the same
The ip addr is written (append) to the output file

subnet_prv = subnet;
memorize subnet

Hi All,

Please check this.....

************************************************** *********
# pre - req : temp should contain all ur input ;

for i in ` sed 's/\./#/3' temp | cut -f 1 -d "#" | sort | uniq `
do
grep $i temp >> $i.log ;
done ;

************************************************** *********


Best Regards,
Hanuman.

Another way to do the work ...

The advantage of 'awk' is that the input file is read only one time, with
this sed/grep solution the file is read for each subnet value + 1.

@hanuman

There is little bug in your script ...

For example, if the input file is :
1.0.0.1
1.0.0.2
2.1.0.0

The result is :
1.0.0.log
1.0.0.1
1.0.0.2
2.1.0.0

2.1.0.log
2.1.0.0

This is because, the pattern of the grep command is not anchored.

You can also use '$i." for the grep pattern.