How to use Git submodules to include external repositories?

To include external repositories using Git submodules, you can follow these steps:

1. Initialize the main repository:

   • Create a new repository or navigate to the existing repository's location in your system.
   • Open the command line or terminal and navigate to the repository directory.
   • Initialize a new Git repository if it's not already initialized by running the command: git init

2. Add a submodule:

   • Identify the external repository that you want to include as a submodule.
   • Get the URL of the external repository. You can find this on the repository's homepage.
   • In the command line or terminal, navigate to the root directory of your main repository.
   • Run the following command to add the submodule: git submodule add <URL of external repository>
     • For example: git submodule add https://github.com/example/repo.git

3. Commit the changes:

   • Run the command: git commit -m "Added submodule <name>". Replace <name> with an appropriate name that represents the submodule you added.

4. Update the submodule:

   • To retrieve the latest changes from the external repository, navigate inside the submodule directory in your local repository.
   • Run the command: git submodule update --remote
     • This fetches the latest changes from the submodule repository and updates it in your main repository.

5. Commit and push:

   • After updating the submodule, navigate back to the root directory of your main repository.
   • Run the command: git commit -am "Updated submodule <name>" to commit and stage the changes.
   • Finally, push the changes to the remote repository using: git push

Now your main repository includes the external repository as a submodule. Other users can also clone your repository and update the submodule to get the latest changes from the external repository.