git: Show index diff in commit message as comment

Question

When git commit open the message editor is shows a brief status, something like this:

# Please enter the commit message for your changes. Lines star         


        

Answer 1

I've put the following lines in .git/hooks/prepare-commit-msg to get a commented out diff:

#!/bin/bash

if [ "$2" == "" ] ; then
    git diff --staged -p --stat 2> /dev/null | awk '{ printf "#"; print}' >> "$1"  2>/dev/null
fi

This way you can not only comment out the diff, but also add more info (like the stat option does).

Edit: Also git commit --verbose does not include the diff to the commit message this way would do without the #s.