An attempt to rewrite author/comitter name/email for all commits in a git repo

gistfile1.sh

#!/bin/sh

git filter-branch --env-filter '

cn="Rhubarb Sin"
cm="rhubarbsin@gmail.com"
an="Rhubarb Sin"
am="rhubarbsin@gmail.com"

export GIT_AUTHOR_NAME="$an"
export GIT_AUTHOR_EMAIL="$am"
export GIT_COMMITTER_NAME="$cn"
export GIT_COMMITTER_EMAIL="$cm"
' -f -- --all