# Git cheatsheet

## Creating a repository
```bash
git init
```
Creates new git repository in current directory.

```bash
git clone <url> (<path>)
```
Clones the repository at the specified url. If no path is specified, the repository will
be cloned into a directory with the same name as the remote repository.


## Branches
```bash
git branch
```
Lists all branches in the repository.

```bash
git branch <branch-name>
```
Creates a new branch with the given name.

```bash
git switch <branch-name>
```
Switches to the specified branch.

```bash
git merge <branch-name>
```
Merges the specified branch into the current branch.


## Making changes
```bash
git status
```
Shows the status of the repository. This includes the current branch and files that have been modified.

```bash
git diff [--staged]
```
Shows the changes that have been made to the files in the repository. Use `--staged` to see changes that have been added to the staging area.

```bash
git add <file>
```
Adds the specified file to the staging area.

```bash
git reset (<file>)
```
Removes the specified file from the staging area. If no file is specified, all files are removed.

```bash
git commit (-m "<message>")
```
Commits all changes in the staging area to the current branch. If the `-m` flag is omitted, a text editor will open to write a commit message.

```bash
git commit --amend
```
Adds the staged changes to the last commit. This can be used for fixing typos in the commit message.


## Undoing changes
```bash
git restore <file>
```
Restores the specified file to the state of the last commit. This undoes uncommitted changes.

```bash
git revert <commit>
```
Creates a new commit that undoes the changes of the specified commit. Use `git log` to find the hash of the commit.

```bash
git reset --hard <commit>
```
Resets the current branch to the specified commit. DANGER: This will remove all changes after the specified commit. Prefer `git revert`.


## Looking at the history
```bash
git log (--oneline)
```
Shows all past commits on the current branch. Use `--oneline` to show a more compact view.

```bash
git show <commit>
```
Shows the changes of the specified commit. Use `git log` to find the has of the commit.


## Remote repositories
```bash
git remote add <remote> <url>
```
Adds a new remote repository with the specified name (e.g. `origin` or `upstream`) and url. Origin is automatically created when cloning a repository.

```bash
git push <remote> <branch>
```
Pushes the specified branch to the remote repository.

```bash
git fetch <remote>
```
Fetches changes from the remote repository.

```bash
git pull <remote> <branch>
```
Fetches changes from the remote repository and merges them into the current branch.


## Typical workflow
```bash
# 1. Fork the repository on GitHub / git.aspp.school

# 2. Clone the repository
git clone <fork-url>
git remote add upstream <upstream-url>

# 3. Create a new branch
git branch <topic-branch>
git switch <topic-branch>

# 4. Make changes to the code

# 5. Add and commit changes
git add file1 file2 ...
git commit -m "<message>"

# 6. Push changes to your fork
git push origin <topic-branch>

# 7. Create a pull request on GitHub / git.aspp.school

# 8. Wait for the pull request to be reviewed and merged

# 9. Pull changes from the remote repository
git switch main
git pull upstream main
```

Whenever the remote repository is updated (i.e. when a pull request is merged), you need to pull the changes into your local repository.
```bash
git switch main
git pull upstream main

# If you have an active topic branch, you need to merge main / rebase on main:
git switch <topic-branch>
git merge main --> preferred
git rebase main --> if you know what you are doing
```


## Getting help
```bash
git help <command>
```
Shows the manual page for the specified command (`add`, `commit`, `push`, etc.).

## Additional docs
- Official Git documentation (mildly useful): https://git-scm.com/docs
- https://ohshitgit.com/