comment/delete a particular pattern starting from second line of the matching pattern

Shell Programming and Scripting
1

Hi,

I have file 1.txt with following entries as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
**
**
**

In file 2.txt I have the following entries as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
0789456|332211|10.20.30.40|078945633
1234567|225522|10.20.30.50|123456733
0321654|999999|10.20.30.40|032165433
0456123|777899|10.20.30.40|045612333
***
***
***

I want take the IP Address column from 1.txt and then search it in 2.txt and comment the duplicate entry from second matched pattern.

i.e., i need to have the following output in 2.txt as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
#0789456|332211|10.20.30.40|078945633
#1234567|225522|10.20.30.50|123456733
#0321654|999999|10.20.30.40|032165433
#0456123|777899|10.20.30.40|045612333
***
***
***

Below is the script i wrote but it will comment all the duplicate entries:

for i in `cat 1.txt |cut -d"|" -f3`
do
cat 2.txt |sed "s/^\(.*\|$i\|.*)/#/g" > tmp.txt
mv tmp.txt 2.txt
done

Can some one guide me how to leave the first duplicate entry untouched and comment/delete from second duplicate entry and so on.
:confused:
Please do not close this thread if you do not know the answer.

Thanks
-Imas

2

Is this a home work question?
Assuming that it's not, what is the real world problem of your question?

Regards

3

Yes your assumption is correct and this is a real world problem

What iam trying to do is commenting the duplicate Ip's found in the text file ignoring the first occurance as to be valid IP for a valid mac and from the second occurance onwards commenting the duplicate IPs at the starting of the line.

file 1.txt with following entries as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
**
**
**

file 2.txt with following entries as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
0789456|332211|10.20.30.40|078945633
1234567|225522|10.20.30.50|123456733
0321654|999999|10.20.30.40|032165433
0456123|777899|10.20.30.40|045612333
***
***
***

i need to have the following output in 2.txt as shown:

0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
#0789456|332211|10.20.30.40|078945633
#1234567|225522|10.20.30.50|123456733
#0321654|999999|10.20.30.40|032165433
#0456123|777899|10.20.30.40|045612333
***
***
***

The correct script i wrote is

for i in `cat 1.txt |cut -d"|" -f3`
do
cat 2.txt |sed "s/^\(.*\|$i\|.*)/#\1/g" > tmp.txt
mv tmp.txt 2.txt
done

But the above script will comment all the occurance.

Your help is appreciated.

Thanks
-imas

4

awk:

nawk 'BEGIN{FS="|"}
{
if(NR==FNR)
	a[$3]=0
else
{
	a[$3]++
	if(a[$3]>=2)
		print "#"$0
	else
		print $0
}
}' 1.txt 2.txt
5

Hi Summer_Cherry,

Million thanks for giving me the piece of code which will comment starting from second occurance of matched pattern from the starting of line.

intelsol2>cat 1.txt
0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
intelsol2>cat 2.txt
0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
0789456|332211|10.20.30.40|078945633
1234567|225522|10.20.30.50|123456733
0321654|999999|10.20.30.40|032165433
0456123|777899|10.20.30.40|045612333
intelsol2>
nawk 'BEGIN{FS="|"}
{
if (NR==FNR)
a[$3]=0
else
{
a[$3]++
if (a[$3]>=2)
print "#"$0
else
print $0
}
}' 1.txt 2.txt >3.txt
intelsol2>cat 3.txt
0152364|134444|10.20.30.40|015236433
0233654|122555|10.20.30.50|023365433
#0789456|332211|10.20.30.40|078945633
#1234567|225522|10.20.30.50|123456733
#0321654|999999|10.20.30.40|032165433
#0456123|777899|10.20.30.40|045612333
intelsol2>

Also thanks a lot for unix forum guys "you ppl rock!!!"

FYI, i was trying to search for this code since all the weekend and went through sed manual "Sed - An Introduction and Tutorial" sub topic (/1, /2, etc. Specifying which occurrence) however was unlucky in trying all the trial and error method.

Also Summer could you please explain me the code you have written so that i can understand it in a better way.

Again thanks a lot and you can close this thread.

Thanks
-imas