When managing projects with Git, the .gitignore file is the most commonly used tool for exclusion rules. However, did you know that Git also provides several other ways to ignore files, each suited for different scenarios? Today, we’ll explore these methods to help you more flexibly control which files Git tracks.

1. .git/info/exclude：Local Repository Exclusive Exclusion Rules¶

If you only want to ignore certain files within the current repository and don’t need to share these rules with other team members, use the .git/info/exclude file.

• Location: In the .git folder at the root of your Git repository, the path is .git/info/exclude.
• Features:
• Only effective for the current repository and not committed to the version repository (so different users can have different exclusion rules).
• Usage is similar to .gitignore: Simply add the files or directories you want to ignore.
• Steps:
  1. Open the terminal and navigate to the project root directory.
  2. Execute touch .git/info/exclude (if the file doesn’t exist).
  3. Open the file with a text editor and add the rules to ignore, e.g.:

     # Ignore local log files
     logs/*.log
     # Ignore temporary cache files
     temp/
     # Ignore personal IDE configuration files
     .idea/workspace.xml

4. Save the file. Git will automatically ignore these files without additional operations.

2. git update-index --assume-unchanged：Temporarily Ignore Tracked Files¶

When you need to ignore a file already tracked by Git (e.g., a local configuration file) but don’t want to delete it, .gitignore may not work directly (since .gitignore only applies to untracked files). In this case, use this command:

• Applicable Scenario: A file already tracked by Git that you know will be frequently modified, but you don’t want Git to prompt you about changes every time.
• Steps:
  1. Suppose you have a tracked local configuration file config.ini:

     # Ensure the file is already tracked (if not, add it first)
     git add config.ini

2. Set to ignore modifications:

     git update-index --assume-unchanged config.ini

3. Unignore the file:

     git update-index --no-assume-unchanged config.ini

• Notes:
• This command is only valid for the current branch, and settings are independent across branches.
• If the file is modified by an external tool (e.g., an editor auto-formats it), Git may fail to detect the change, leading you to think the file hasn’t changed when it actually has.

3. git update-index --skip-worktree：Strict Worktree Ignoring¶

This is a more powerful command than --assume-unchanged, mainly used to protect files from being modified by Git tracking, suitable for sensitive files (e.g., password configurations).

• Difference from --assume-unchanged:
• --assume-unchanged only assumes the file hasn’t been modified and allows Git to check the staging area.
• --skip-worktree forces Git to skip checking the file in the working tree, and even if the file content differs from the staging area, Git won’t prompt you.
• Steps:

  # Set to ignore
  git update-index --skip-worktree config.ini
  # Unignore
  git update-index --no-skip-worktree config.ini

4. git rm --cached：Remove Tracked Files from the Staging Area¶

If you want to completely remove a tracked file from the repository while keeping the local file (e.g., if you accidentally committed a large file or temporary file), use this method:

• Applicable Scenario: A file already tracked by Git that you now want to remove from the repository but keep locally.
• Steps:

  # Remove the file from the staging area (keep local)
  git rm --cached large_file.dat
  # Commit the change
  git commit -m "Remove large_file.dat from version control"

• Notes: After execution, Git will delete the file from the staging area and repository, but the local file remains. It won’t be included in future commits.

5. Choosing the Right Method¶

Summary¶

• Daily General Exclusion: Use .gitignore first and share it with the team.
• Personal Local Special Needs: Use .git/info/exclude without affecting others.
• Ignore Modifications of Tracked Files: Use --assume-unchanged or --skip-worktree.
• Remove Tracked Files from Repository: Use git rm --cached.

By mastering these methods, you can more flexibly manage the scope of files Git tracks, avoiding a bloated repository or sensitive information leaks. Choose the appropriate method based on your project needs to ensure smoother collaboration!