Bash Script to Update Git Commit History - Change Author and Committer Information

update-git-author.sh

# This script updates author and committer information for past Git commits.
# It modifies commit history where the specified OLD_EMAIL is found, 
# replacing it with the CORRECT_NAME and CORRECT_EMAIL.

# 🔥 Why Use This Script?
# - Correct misattributed commits after email address changes.
# - Update author information across all branches and tags.
# - Maintain consistency in commit history before sharing a project.

# 📦 How It Works:
# - Accepts OLD_EMAIL, CORRECT_NAME, and CORRECT_EMAIL as inputs.
# - Applies changes to both author and committer information.
# - Updates all branches and tags in the repository.

```bash
#!/bin/sh

git filter-branch --env-filter '
OLD_EMAIL="[email protected]"
CORRECT_NAME="ABC"
CORRECT_EMAIL="[email protected]"
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

```