How do I revert a Git repository to a previous commit?

When you need to restore a Git repository to a previous commit, several methods are available. Here are two commonly used approaches:

1. Using the git checkout command

The git checkout command allows you to switch to a specific commit in the repository. This method does not alter the history of the main branch and is suitable for temporarily viewing or testing older versions.

Steps:

1. First, open your terminal and navigate to the Git repository directory.
2. Use git log to view the commit history and identify the hash of the commit you want to restore.
3. Execute git checkout [commit-hash] to switch the repository to that commit. Replace [commit-hash] with the hash you found.

For example, to restore to the commit with hash abc1234, you would enter:

bash
git checkout abc1234

Note: This places your working directory in a "detached HEAD" state. This means any new commits will not affect the existing branches. If you want to preserve these changes, you should create a new branch.

2. Using the git reset command

If you need to revert the current branch's history to a specific commit, use git reset. This modifies the branch history, so exercise caution when working in collaborative projects.

Steps:

1. Similarly, open your terminal and navigate to the Git directory.
2. Use git log to view the commit history and find the hash of the target commit.
3. Execute git reset --hard [commit-hash] to hard reset to that commit. Replace [commit-hash] with the hash you found.

For example, to restore to the commit with hash abc1234, you would enter:

bash
git reset --hard abc1234

Note: The --hard option discards all changes in the working directory. Ensure you have backed up your work before executing.

Real-World Example

In a previous project, we needed to restore to the previous version for bug fixing because the latest version introduced unstable features. By executing the git reset --hard command, we successfully restored the codebase to a stable state and then created a new branch for the bug fixes. This approach ensured the stability of the main branch while facilitating smooth bug resolution.

In summary, the choice of method depends on your specific needs, whether you need to affect the project history, and your working environment.