How to Ignore Changes in Tracked Files with Git?

When using Git as a version control system, you might sometimes need to make local changes to certain files without pushing those changes to the remote repository. In such cases, you can use the git update-index command to temporarily ignore changes to tracked files.

Specific Steps:

1. Use the git update-index --assume-unchanged <file> command This command instructs Git to temporarily ignore any modifications to the specified file. For example, to ignore changes to the configuration file config.ini, run:

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

   After this, regardless of how you modify the local config.ini file, Git will treat it as unchanged.

2. View files set to ignore changes To identify files configured to ignore changes, use:

   shell
   git ls-files -v | grep '^[a-z]'

   Here, git ls-files -v lists all files and their statuses, and statuses starting with lowercase letters indicate files set to assume-unchanged.

3. Restore tracking of file changes If you later want to resume tracking changes for a file, use:

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

   For instance, to restore tracking for config.ini, run:

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

Real-World Scenario:

Suppose you are developing a multi-person project where the database.config file contains sensitive information. Each developer needs to modify this file based on their local environment, but these modifications should not be committed to the public repository. Using this technique, each developer can locally ignore changes to this file, preventing sensitive information leaks or frequent merge conflicts.

Important Notes:

While this method is useful for temporarily ignoring file changes, it does not alter the physical state of the file; the file remains modified locally. If you need to completely exclude a file, consider adding rules to the .gitignore file. However, this only applies to untracked files. For tracked files, you must first remove them from the repository (without deleting the physical file), then add them to .gitignore.