Git Utility Scripts

A small collection of opinionated shell scripts that automate repetitive (and sometimes dangerous!) Git maintenance tasks.

These scripts grew out of day-to-day work at the command line and are shared in the hope that they might save you a few keystrokes—or a late-night panic.

⚠️ Use at your own risk. Several of the commands below rewrite Git history or perform force-pushes. Make sure you understand what they do before running them against important repositories.

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Contents

Script	What it does
reset-to-remote.sh	Resets all local branches so they exactly match their origin/* counterparts while safely stashing & restoring any uncommitted changes.
mirror.sh	Performs a one-shot --mirror clone of a source repository and pushes it to a destination remote—handy for backups or migrations.
prepare-email-mapping.sh	Scans every commit in a repository and creates/updates an email-mapping.txt file containing every unique name <email> identity it finds.
rewrite-emails.sh	Uses git-filter-repo and the email-mapping.txt file to rewrite author/committer information across the entire history of a repository.

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Prerequisites

• Bash 4+
• Git 2.20+
• git-filter-repo (only required for rewrite-emails.sh). Install via:

pip install git-filter-repo  # or see the upstream repo for other options

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Quick start

Clone this repository somewhere on your machine and call the scripts via their absolute path (or add it to your PATH):

git clone https://github.com/coreprocess/git-scripts.git

Each script is self-contained and prints progress messages as it runs.

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Usage

1. reset-to-remote.sh

Synchronises every local branch with the matching branch on origin:

cd /path/to/repo
/path/to/git-scripts/reset-to-remote.sh

What happens:

1. git fetch --all --prune pulls the latest state of every remote.
2. Your current branch name is stored.
3. Uncommitted changes (tracked and untracked) are stashed.
4. Each local branch is checked out and hard-reset to origin/<branch>.
5. Your original branch is checked out again and the stash is popped (if one was created).
6. git gc --prune=now cleans up dangling objects.

2. mirror.sh

Mirror an entire repository—including all refs, branches, tags, and notes—to another remote:

/path/to/git-scripts/mirror.sh git@github.com:org/source.git git@github.com:org/backup.git

A temporary directory is created automatically and removed afterwards.

3. prepare-email-mapping.sh

Generate or update an email-mapping.txt file that will later be consumed by rewrite-emails.sh:

/path/to/git-scripts/prepare-email-mapping.sh https://github.com/org/repo.git

# Edit email-mapping.txt so that each line follows the format
#   Correct Name <correct.email@example.com> <old.email@example.com>

The script:

• Performs a --mirror clone in a temp directory.
• Extracts all unique author and committer identities.
• Appends any previously unseen identities to email-mapping.txt in the current working directory.

4. rewrite-emails.sh

Rewrite the entire history of a repository using email-mapping.txt:

/path/to/git-scripts/rewrite-emails.sh https://github.com/org/repo.git

A safety backup (<repo>-backup.git) is created next to a working clone (<repo>-rewrite.git). The working clone's history is rewritten and force-pushed back to the original URL.

After verifying everything looks good, you can remove the backup directory.

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Recommended author/email replacement workflow

# 1. Prepare the mapping file
/path/to/git-scripts/prepare-email-mapping.sh <repo-url>

# 2. Edit email-mapping.txt until all identities are mapped to their desired form
cursor email-mapping.txt

# 3. Rewrite history
/path/to/git-scripts/rewrite-emails.sh <repo-url>

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Contributing

Bug reports and pull requests are welcome! Feel free to open an issue with questions or improvements.

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License

This project is released under the MIT License. See LICENSE for details.