Introduction
Adding a file to a .gitignore file informs Git to exclude it from tracking. However, if the file was already tracked prior to its inclusion in .gitignore, some extra steps are necessary to stop tracking it without removing the file itself from the filesystem. This tutorial will detail the process of handling such files, using a step-by-step approach to make your Git repositories perform as desired.
Understanding .gitignore
Before diving into the commands, it’s important to understand the purpose and function of the .gitignore file. This file tells Git which files or directories to ignore when looking for untracked files, which means that the files will not be included in commits and will not be tracked. This is especially useful for temporary files, logs, or specific configuration files that should not be shared among all developers through the repository.
Here’s a simple .gitignore file excluding logs and temporary files:
*.log
*.tmp
Stopping Git from Tracking Files
Suppose you’ve already committed a file that you now want to ignore. Simply adding this file to .gitignore will not remove it from the repository’s history, nor prevent it from being tracked in future commits. To instruct Git to cease tracking the file, you must use the git rm --cached command.
Basic: Removing a Single File
Let’s start with the most basic situation: removing a single file from Git’s tracking list. The following steps are assuming you have already added the file to the .gitignore.
echo 'config.ini' >> .gitignore
git rm --cached config.ini
git commit -m "Stop tracking config.ini"
This will remove config.ini from the repository, but it will stay in your working directory.
Intermediate: Removing Multiple Files
If you have multiple files to remove from the tracked list, you can do so with one command:
git rm --cached log/* tmp/*
git commit -m "Stop tracking logs and temp files"
The asterisks (*) serve as wildcards, signaling Git to untrack all the files in the specified directories.
Advanced: Working with Wildcards and Globbing
For more complex patterns and ranges of files, Git supports shell-style wildcards, or glob patterns. This can include recursive patterns using double asterisks:
git rm --cached -r *.txt
git commit -m "Untrack all text files in repository recursively"
This would recursively untrack all .txt files across all directories in the repository.
Maintaining a Clean Repository
Once the files are untracked, you might still need to clean your repository to remove ignored files. However, be careful as this operation is not reversible. If you accidentally remove something important, it may be difficult to recover.
git clean -xdf
This command will remove all files from the working tree that are not under version control.
Conclusion
Instructing Git to stop tracking a file once it’s added to .gitignore is straightforward but requires some hands-on steps. By utilizing the git rm --cached command, you can efficiently manage your repository’s tracked files, keeping only what’s necessary, while leaving the ignored files undisturbed in your working directory.
