Creating a Local Repository

Overview

Teaching: 10 min
Exercises: 0 min

Questions

• How do I store a repository locally?

Objectives

• Clone a local Git repository from a remote GitHub repository.

Once Git is configured, we can start using it. Let’s choose the right directory for our work and then move into that directory:

$ cd ~/Desktop
$ mkdir GRAD521_DMP
$ cd GRAD521_DMP

In this example we will be saving the repository in our Desktop, but feel free to navigate to other directories that may be more apropriate. To navigate directories through the command line you can use the command cd to change directories (like we did above to get into the Desktop and GRAD521 directory) and .. to move up a directory. The command ls will help you see the files and folders in the directory.

Then we tell Git to clone our remote repository that we created in GitHub.

$ git clone https://github.com/username/GRAD521_DMPSurname_2019.git .

If we use ls to show the directory’s contents, it appears that the two documents from our GitHub directory have appeared into the directory:

$ ls

README.md  index.md

If we add the -a flag to show everything, including hidden files, we can see that Git has created a hidden directory within GRAD521_DMP called .git:

$ ls -a

./         ../        .git/      README.md  index.md

Git stores information about the project in this special sub-directory. If we ever delete it, we will lose the project’s history.

We can check that everything is set up correctly by asking Git to tell us the status of our project:

$ git status

On branch master
Your branch is up-to-date with 'origin/master'.
nothing to commit, working tree clean

Places to Create Git Repositories

Dracula starts a new project, moons, related to his planets project. Despite Wolfman’s concerns, he enters the following sequence of commands to create one Git repository inside another:

$ cd             # return to home directory
$ mkdir planets  # make a new directory planets
$ cd planets     # go into planets
$ git init       # make the planets directory a Git repository
$ mkdir moons    # make a sub-directory planets/moons
$ cd moons       # go into planets/moons
$ git init       # make the moons sub-directory a Git repository

Why is it a bad idea to do this? (Notice here that the planets project is now also tracking the entire mars repository.) How can Dracula undo his last git init?

Solution

Git repositories can interfere with each other if they are “nested” in the directory of another: the outer repository will try to version-control the inner repository. Therefore, it’s best to create each new Git repository in a separate directory. To be sure that there is no conflicting repository in the directory, check the output of git status. If it looks like the following, you are good to go to create a new repository.

repository as shown:

$ git status

fatal: Not a git repository (or any of the parent directories): .git

Note that we can track files in directories within a Git:

$ touch moon phobos deimos titan    # create moon files
$ cd ..                             # return to planets directory
$ ls moons                          # list contents of the moons directory
$ git add moons/*                   # add all contents of planets/moons
$ git status                        # show moons files in staging area
$ git commit -m "add moon files"    # commit planets/moons to planets Git repository

Similarly, we can ignore (as discussed later) entire directories, such as the moons directory:

$ nano .gitignore # open the .gitignore file in the texteditor to add the moons directory
$ cat .gitignore # if you run cat afterwards, it should look like this:

moons

To recover from this little mistake, Dracula can just remove the .git folder in the moons subdirectory. To do so he can run the following command from inside the ‘moons’ directory:

$ rm -rf moons/.git

But be careful! Running this command in the wrong directory, will remove the entire git-history of a project you might wanted to keep. Therefore, always check your current directory using the command pwd.

Key Points

• git clone clones a repository.