Change commit author & email in all commits of a repository

update_commit_email.sh

#!/bin/sh

if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <repo owner> <repo name>"
fi

REPO_OWNER="$1"
REPO_NAME="$2.git"

# Clone the repo
git clone --bare "https://github.com/$REPO_OWNER/$REPO_NAME"

# Change to the raw repo directory
cd $REPO_NAME

# Taken from https://help.github.com/en/articles/changing-author-info
git filter-branch --env-filter '

OLD_EMAIL="old.commit.email@email.com"
CORRECT_NAME="Correct author name"
CORRECT_EMAIL="old.commit.email@email.com"

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

# Push changes to remote
git push --force --tags origin 'refs/heads/*'

# Delete the raw repo directory
cd ..
rm -rf $REPO_NAME

Usage

Make the script an executable with

chmod +x update_commit_email.sh

Run it with

./update_commit_email.sh <github username> <github repo name>

Configuring

You will have to directly modify the script contents, lines 19-21, with the correct details you need.

Notes

It's a very crude script, some user friendliness is appreciated. Feel free to improve upon it (and share it here).