**Course Title:** Version Control Systems: Mastering Git **Section Title:** Getting Started with Git **Topic:** Viewing commit history with `git log`. Now that you've learned the basic Git commands and understand the Git directory structure, it's time to explore how to view your commit history. In this topic, you'll learn how to use the `git log` command to view the commit history of your repository. ### What is `git log`? `git log` is a command that displays the commit history of a repository. It shows a list of all commits made to the repository, including the author, date, and commit message. This command is useful for tracking changes, identifying who made changes, and determining when changes were made. ### Basic Usage of `git log` To view the commit history, navigate to your repository directory and run the following command: ```bash git log ``` This will display a list of commits, with the most recent commit at the top. Each commit is represented by a unique identifier, known as a commit hash. ### Understanding `git log` Output The `git log` output typically includes the following information: * `commit hash`: a unique identifier for each commit * `Author`: the name and email of the person who made the commit * `Date`: the date and time the commit was made * `commit message`: a brief description of the changes made in the commit Example output: ``` commit 654d565c7af5 (HEAD -> master) Author: John Doe <john.doe@example.com> Date: Fri Jan 1 12:00:00 2021 +0000 Initial commit ``` ### Options for Customizing `git log` Output `git log` has several options that allow you to customize the output. Here are a few common ones: * `-p` or `--patch`: shows the actual changes made in each commit * `--stat`: shows the number of lines added or removed in each commit * `--graph`: displays a graphical representation of the commit history * `--all`: shows all commits, including those that are not part of the current branch Example: ```bash git log -p ``` This will show the actual changes made in each commit. ### Using `git log` with Branches When working with branches, you can use `git log` to view the commit history of a specific branch. To do this, specify the branch name along with the `git log` command: ```bash git log origin/master ``` This will show the commit history of the `origin/master` branch. ### Using `git log` with Dates You can also use `git log` to view the commit history within a specific date range. To do this, use the `--since` and `--until` options: ```bash git log --since=2020-01-01 --until=2021-01-01 ``` This will show the commit history between January 1, 2020, and January 1, 2021. ### Practical Takeaways * Use `git log` to view the commit history of your repository * Customize the output using options like `-p`, `--stat`, `--graph`, and `--all` * Use `git log` with branches and dates to view specific commit histories ### Additional Resources For more information on `git log`, see the official Git documentation: [git-scm.com](https://git-scm.com/docs/git-log) ### Exercise Try running `git log` in your own repository to view the commit history. Experiment with different options to customize the output. ### Next Topic Now that you've learned how to view your commit history, you'll learn how to undo changes using `git checkout`, `git reset`, and `git revert` in the next topic. **Do you have any questions or need help with this topic? Leave a comment below.**