Shell Programming and Scripting

I have two files file1 and file 2
both are having multiple coloumns.i want to select only two columns.
i used following code to get the desired columns,with ',' as delimiter

cut -d ',' -f 1,2 file1 | sort > file1.new
cut -d ',' -f 1,2 file2 | sort > file2.new

I want to get the coloums that are having the difference in both the files
I used follwing code for that

comm -3 file1.new file2.new > file3

Now i have the output in the following format in the file3
1234,def
1234,abc 2345,abc
2345,def
5678,fgh
......... 5678,ijk
......... .........
and so on and so on


Here comes my problem. I have to generate a mail in such a way that

1234 has a change from abc to def and
2345 has a change from def to abc and
5678 has a change from fgh to ijk and so on

please help me in writing the script for the above
Thanks in advance...

Try this perhaps (untested but should give you some ideas):

Code:

cut -d ',' -f 1,2 file1 | sort -t, -k 1,1 > file1.new
cut -d ',' -f 1,2 file2 | sort -t, -k 1,1 > file2.new
join -t, -1 1 -2 1 file1.new file2.new | awk -F, '$2 != $3'