How to get diff to report summary of new, changed and deleted lines

I want to have summary of difference between two files. Expected output is count of new, deleted and changed lines. Does diff readily provides such output? If not is there any script/utility available which helps in getting the summary.

I think you are looking for diffstat. Simply pipe the output of diff -u to diffstat and you should get something like this.

 include/net/bluetooth/l2cap.h |    6 ++++++
 net/bluetooth/l2cap.c         |   18 +++++++++---------
 2 files changed, 15 insertions(+), 9 deletions(-)

For those using Git or Mercurial, a quick way to see such a summary of ones unstaged changes:

git diff --stat
hg diff --stat