Add submodules basics

### Git

* [Configuring using `git config`](git/configuring-using-git-config.md)

* [Pushing to multiple remote repos](git/pushing-to-multiple-remote-repos.md)

* [Submodules basics](git/submodules-basics.md)

* [Useful aliases: `push --force-with-lease`](git/useful-aliases-push-force-with-lease.md)

### Linux

Submodules basics

=================

`git` submodules are especially useful when we require the use of code from

different repositories, examples include third-party libraries and frameworks.

> Submodules allow you to keep a Git repository as a subdirectory of another

Git repository. This lets you clone another repository into your project and

keep your commits separate. - [git-scm](https://git-scm.com/book/en/v2/Git-Tools-Submodules)

### Add submodules to an existing project

```

git submodule add GIT_REPO_URL

```

By default, submodules will add the subproject into a directory named the same

as the repository.

### The `.gitmodules` file

The above command automatically adds the file to the root directory of the

original repository. The file lists all the submodules added to the project:

```

[submodule "SUBMODULE_REPO_NAME"]

    path = PATH_TO_SUBMODULE_FOLDER

    url = SUBMODULE_REPO_URL

...

```

This file can be manually created and edited.

### Working with projects with submodules

Two ways to do it, first is to clone the original repo and running a couple of

commands to download the submodules:

```

git clone ORIGINAL_GIT_REPO_URL

git submodule init

git submodule update

```

The second way is by passing the `recursive` flag to the `git clone` command:

```

git clone --recursive ORIGINAL_GIT_REPO_URL

```