# Advanced Git Commands

## [`git log`](https://git-scm.com/docs/git-log): View commit details

Sample output of git log. Use `j` and `k` on the keyboard to scroll up and down and `q` to exit the log view.

```
commit 4bdffb07c5abd0d41388c991dc03661be07fe6d0 (HEAD -> main, origin/main, origin/HEAD)
Merge: 269f9f4 11690c2
Author: Jiahao <woojiahao1234@gmail.com>
Date:   Fri May 17 21:46:40 2024 +0800

    Merge pull request #7 from francisyzy/main
    
    Update links

commit 11690c25ce187263ff77725647475fee6d5e1faa
Author: francisyzy <francisyzy@me.com>
Date:   Fri May 17 21:37:24 2024 +0800

    Add feedback QR code

commit f5458f36c67c927fcd41e65e29eb5b8a1491d7a1
Author: francisyzy <francisyzy@me.com>
Date:   Fri May 17 17:14:09 2024 +0800

    Update links

commit 269f9f48ddb550da9223d03123279910dd8c5336
Merge: a1fc9bf 01cdd59
Author: Francis Yeo <github@francisyzy.com>
Date:   Fri May 17 12:15:50 2024 +0800

    Merge pull request #3 from woojiahao/main
```

Each log entry will describe what that commit does. Each commit will have a commit hash, author and date.

For example this commit:

```
commit f5458f36c67c927fcd41e65e29eb5b8a1491d7a1
Author: francisyzy <francisyzy@me.com>
Date:   Fri May 17 17:14:09 2024 +0800

    Update links
```

* commit hash is `f5458f36c67c927fcd41e65e29eb5b8a1491d7a1`
* author is `francisyzy <francisyzy@me.com>` *which was set by the author's `git config`*
* date of the commit is `Fri May 17 17:14:09 2024 +0800`
* message of the commit is `Update links`

The git commit history is also viewable on the [Github repository](https://github.com/nushackers/hackertools_materials/commits/main/) itself.

## [`git revert`](https://git-scm.com/docs/git-revert): Revert a commit

Lets you 'undo' a commit. It will undo the changes made by that commit and make a new commit to do so.

Do note that this is not the method of removing sensitive information as commit history can still retrieve it.

There is a [stackoverflow discussion](https://stackoverflow.com/questions/40865425/how-to-remove-sensitive-data-api-key-across-git-commit-history) on how to remove such information and rewrite history. Do note that rewriting history will result in other people's repo being broken.

## [`git reset`](https://git-scm.com/docs/git-reset): Reset HEAD to the commit

This will reset the current HEAD to the commit hash.

Useful reset command that can be used to edit the commit message **before** its being pushed to the remote is: `git reset --soft HEAD~`. The command will reset the files to the commit right before the current commit and leave the files in the latest commit in staged. Allowing you to `git commit -m "Updated message"` to change the git commit message.

## [`git checkout`](https://git-scm.com/docs/git-checkout): Checkout files (and also a branch) commits

You can also use `git checkout <commit hash>` to go to view the files at a specific commit too.

A useful feature to have when you want to check out the files of that commit before you reset to that commit.