concatenate data from different lines

kiloman · 03-01-2011, 04:47 AM

Hi everybody.

I want to concatenate info from different lines from iptables. for exmaple, in my firewall using iptables I have this information.

pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 192.168.1.3 0.0.0.0/0
5 248 ACCEPT all -- * * 0.0.0.0/0 192.168.1.3

This shows how many bytes a user with ip 192.168.1.3 has down- and uploaded. I now want to print out a line that looks like this.

"IP, downloaded bytes, uploaded bytes"

But since informations are split over two lines i don't know how to combine them.

In a real world example there will of course be many more lines.

Hope someone can help.

Thanks.

rizhun · 03-01-2011, 07:15 AM

Hello kiloman,

This feels like homework, so I'll just point you in the general direction

There are several ways to do this.
You could do it all in Perl, or you could do it just from a command prompt.

If you went down the command prompt route, you can join every other line using 'sed':

Code:

$ /your/iptables/command --andopts | sed '$!N;s/\n/ /'

You could then pipe this output through 'awk' and just output the fields you want:

Code:

$ /your/iptables/command --andopts | sed '$!N;s/\n/ /' | awk 'BEGIN { print "IP downloaded-bytes uploaded-bytes" } { print $1 " " $2 " " $3 }'

(the positional parameters used above ($1, $2 and $3) would need setting to whatever field you required, based on the output of the first command)

This code presumes that your iptables command only shows you the data, and there are no column names or other identifiers in the mix. I don't use iptables, so I'm not familiar with the layout.

Good luck!