diff -c file1 file2
*** file1 Tue Jul  7 16:48:22 2009
--- file1 Tue Jul  7 16:49:01 2009
***************
*** 1,7 ****
  one
  two
  three
! for
  five
  six
  seven
--- 1,7 ----
  one
  two
  three
! four
  five
  six
  seven