1234,Joe,pieter,joe@gmail.com,male,22
1235,Shally,Jonse,shally@yahoo.com,female,24
1235,Harry,poter,harry@gmail.com,male,21
1235,Helen,Jairag,helen@gmail.com,female,21
2585,Dinesh,Jairag,helen@gmail.com,female,21

1234,Joe,pieter,joe@gmail.com,male,22
1235,Shally,Jonse,shally@yahoo.com,female,24
1235,Harry,Potter,harry@gmail.com,male,21
1235,Helen,Jairag,helen@gmail.com,female,21

diff F2 F1

3c3
< 1235,Harry,Potter,harry@gmail.com,male,21
---
> 1235,Harry,poter,harry@gmail.com,male,21
4a5
> 2585,Dinesh,Jairag,helen@gmail.com,female,21

1235,Harry,poter,harry@gmail.com,male,21
2585,Dinesh,Jairag,helen@gmail.com,female,21

diff --changed-group-format='%<' --unchanged-group-format='' file1 file2

diff -u File1 File2

--- File1   2012-08-22 11:30:07.000000000 +0200
+++ File2   2012-08-22 11:30:25.000000000 +0200
@@ -1,5 +1,4 @@
 1234,Joe,pieter,joe@gmail.com,male,22
 1235,Shally,Jonse,shally@yahoo.com,female,24
-1235,Harry,poter,harry@gmail.com,male,21
+1235,Harry,Potter,harry@gmail.com,male,21
 1235,Helen,Jairag,helen@gmail.com,female,21
-2585,Dinesh,Jairag,helen@gmail.com,female,21

diff -u data1 data2 |
  awk 'NR > 2 && $0 ~ /^+/ {print substr($0,2)}'

1235,Harry,Potter,harry@gmail.com,male,21

diff -u data2 data1 |
  awk 'NR > 2 && $0 ~ /^+/ {print substr($0,2)}'

1235,Harry,poter,harry@gmail.com,male,21
2585,Dinesh,Jairag,helen@gmail.com,female,21