Summary : A utility which provides statistics based on the output of diff

Description :
The diff command compares files line by line. Diffstat reads the output
of the diff command and displays a histogram of the insertions, deletions
and modifications in each file. Diffstat is commonly used to provide
a summary of the changes in large, complex patch files.

Install diffstat if you need a program which provides a summary of the
diff command's output. You'll need to also install diffutils.

URL : http://dickey.his.com/diffstat/diffstat.html
License : GPL-like