Shell Programming and Scripting

Code:

# cat list.txt
server1
server2
server3
server4

# data to be compared of.
#dns address
1.1.1.1

2.2.2.2

3.3.3.3


#for i in `cat list.txt`
do
grep dns $ i
done

Desired output:

Code:

#cat server1|grep dns
1.2.3.4

Then it will send an email that dns is different, not equal to 1.1.1.1 , 2.2.2.2 and 3.3.3.3

---------- Post updated at 10:52 PM ---------- Previous update was at 10:20 PM ----------

done,,we may clsed this

This is not clear and vague. At a guess you have a number of files, server1, server3, and server4.
File list.txt is a list of these files.

This part isn't clear, but it seems you have another file containing ip addresses, let's call this file valid_addresses.txt.

So file list.txt contains
server1
server3
server4

File valid_addresses.txt contains...
1.1.1.1
2.2.2.2
3.3.3.3

Let's say file server1 contains...
4.4.4.4

Let's say file server3 contains
3.3.3.3

Let's say file server4 contains
2.2.2.2

Then this script x.sh works...

Code:

 #! /bin/ksh 
for i in `cat list.txt`  
do         
    ip=`cat ${i}`        
    if ! grep -q "${ip}" valid_addresses.txt          
    then                  
       echo "DNS IP ${ip} from file ${i} not found in valid_addresses.txt"           
    fi 
done

If you are using bash shell,
change top to !# /bin/bash

and if you want to email
change echo statement to something like...

Code:

 
echo "DNS IP ${ip} from file ${i} not found in valid_addresses.txt" | mailx -s "subject" someuser@host