Mastering the `git obliterate` Command (with Examples)
The git obliterate command is an advanced Git tool used to completely erase files and remove their history from a Git repository. It’s part of the git-extras suite, which offers additional powerful commands for developers who want enhanced functionalities beyond what standard Git provides. The command is particularly useful in instances where sensitive information has been committed or when large or unwanted files need to be purged from a project’s history to clean up the repository. Below, we explore practical use cases of the git obliterate command.
Use case 1: Erase the Existence of Specific Files
Code:
git obliterate file_1 file_2 ...
Motivation:
Imagine that during the development of a project, someone accidentally commits sensitive outdated configuration files like config.yml and passwords.txt into the Git repository. These files were not supposed to be part of the tracked files due to security and compliance implications. Unfortunately, simply removing these files from the latest commit does not eliminate the traces of these files from previous commits. Thus, a solution is needed to erase these files completely from the repository history. The git obliterate command provides a way to purge these files from every commit record where these files appear, ensuring that no trace of them remains.
Explanation:
git obliterate: This initiates the command to remove files entirely from the Git history.file_1 file_2 ...: These placeholders represent the specific files you want to obliterate from your Git history. By listing the files, you instruct Git to search all historical commits, excise these files, and rewrite the commit history to reflect their absence.
Example Output:
When you run this command, the output in your terminal might include success messages indicating the files have been obliterated, such as:
Obliterating file_1 from history...
Obliterating file_2 from history...
Rewriting history...
All specified files have been successfully obliterated and commits rewritten.
Use case 2: Erase the Existence of Specific Files Between 2 Commits
Code:
git obliterate file_1 file_2 ... --commit_hash_1..commit_hash_2
Motivation:
There are scenarios where not all of your project’s history should be changed; instead, you might need to target a specific range of commits. For example, suppose a set of deprecated images, namely logo_old.png and banner_old.png, were added between two particular commits — a1b2c3d and e4f5g6h. You may decide to clean up the repository by removing these large and unnecessary files without influencing other parts of the project’s history. In such cases, obliterating these files between specific commits restricts the changes to that range, minimizing the risk of unintended alterations to the remainder of the project history.
Explanation:
git obliterate: This command initializes the process of erasing specified files from the Git history.file_1 file_2 ...: These represent the files you intend to excise. By specifying these, you’re targeting the particular files to be removed.--: Signals the end of command options and the start of commit-part specification.commit_hash_1..commit_hash_2: These hashes define the range between which the obliteration should occur. It selects commit range inclusive of the first hash and up to the second hash, ensuring changes are restricted within this scope.
Example Output:
Executing this command, you could see an output similar to the following, reassuring you that the removal operation has been confined between the specified commits:
Obliterating file_1 from history between a1b2c3d and e4f5g6h...
Obliterating file_2 from history between a1b2c3d and e4f5g6h...
Rewriting commits in the specified range...
Files successfully removed within the specified commit range.
Conclusion:
The git obliterate command is a robust tool within the git-extras suite designed to manage your repository’s history with precision. Whether you need to erase sensitive files entirely from your project’s past or target specific intervals between commits for cleanup, understanding and correctly deploying this command will help maintain your repository’s integrity and security.
