Making sure go source passes gofmt before committing

Here is a nice little snippet to make sure your go code passes gofmt before committing. Put this in .git/hooks/pre-commit:

#!/bin/sh

set -e

d=`mktemp -d --tmpdir gofmtcheck-XXXXXX`

git checkout-index --prefix "$d/" -a

ret=`find . -regex '.*\.go$' -exec gofmt -d '{}' \;`

if [ ! -z "$ret" ]; then
    echo "Not all go files are well formatted:"
    echo
    echo "$ret"
    echo

    exit 1
fi

Extra points for the person who extends this to stage the suggestions from gofmt in the index on request!