Simple script for updating the commit author in a repository across all branches

git-author-rewrite.sh

#!/bin/sh

git filter-branch --env-filter '
OLD_EMAIL="OLD EMAIL ADDRESS"
CORRECT_NAME="NEW NAME"
CORRECT_EMAIL="NEW EMAIL"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags

# Then run to update remote: git push --force --tags origin 'refs/heads/*'
# Command to Remove Back-up branch: git update-ref -d refs/original/refs/heads/master