How to Ignore Files Locally in Git Without Affecting Global Settings

Introduction

When working with Git, you might encounter situations where certain files should be ignored locally on your machine without affecting others who use the same repository. This tutorial explores how to manage untracked or tracked files that shouldn’t be committed to a shared Git repository. We’ll delve into multiple methods and commands that allow for this local customization effectively.

Understanding .gitignore Files

In Git, .gitignore files are used to specify intentionally untracked files that should not be included in the repository. However, these files do not influence locally tracked files that have already been added to the version control system. To achieve finer-grained control over local changes without affecting global or shared settings, we need other solutions.

Local Exclusions

Using .git/info/exclude

For repository-specific exclusions that don’t need to be shared with others:

1. Navigate to your Git repository’s root directory.
2. Open or create the .git/info/exclude file.
3. Add patterns similar to those you would use in a .gitignore file.

This method ensures that these exclusions are only applicable locally, without affecting other collaborators’ work environments.

Using core.excludesFile

For patterns that should be ignored globally across all repositories on your machine:

1. Configure a global ignore file by running:

   git config --global core.excludesfile ~/.gitignore_global
   

2. Add the desired exclusion patterns to ~/.gitignore_global.

This approach is useful for universally ignoring files like temporary compiler output (*.pyc, *.o) across all your projects.

Ignoring Local Changes

Using update-index with –assume-unchanged

To ignore changes made to already tracked files locally:

1. Run:

   git update-index --assume-unchanged <file>
   

2. This command tells Git to temporarily ignore changes in the specified file(s).

Reversal for when you want to track these changes again:

git update-index --no-assume-unchanged <file>

Using update-index with –skip-worktree

A more robust alternative to --assume-unchanged, which doesn’t get undone by certain Git operations like pull:

1. Run:

   git update-index --skip-worktree <file>
   

2. This command will skip the file during merge, rebase, or other work tree updates.

To revert this action and start tracking changes again:

git update-index --no-skip-worktree <file>

Creating Git Aliases for Ease of Use

You can create Git aliases to simplify these commands:

1. Open your .gitconfig file.

2. Add the following alias configurations:

   [alias]
       ignore = update-index --assume-unchanged
       unignore = update-index --no-assume-unchanged
       ignored = !git ls-files -v | grep "^[[:lower:]]"
   

3. Now, use git ignore <file> to mark files as ignored locally and git unignore <file> to reverse this action.

Best Practices

• Use patterns in your .gitignore or exclusion files instead of listing specific file names where possible.
• Regularly review and clean up local exclusions that are no longer necessary.
• Be cautious with the use of --assume-unchanged as it can lead to unexpected behavior if forgotten.

Conclusion

By using the methods outlined in this tutorial, you can effectively manage local Git configurations without impacting other users or altering global settings. Whether through .git/info/exclude, specific commands like update-index, or by setting up convenient aliases, you have multiple tools at your disposal to ensure a clean and tailored development environment.