compsoc-git-giag

Generating your ssh key

Creating an ssh key and adding it to your github account means your computer will have access to your account's repositories.

Generating ssh keys

ssh-keygen -t rsa -b 2048

From here, you will be given some prompts, one for the file location (at university the .ssh folder will have to go in your /u drive, on personal computers, the .ssh folder will generally live in the /c drive), the next two will be to add a passphrase; the passphrase doesn't need to be added.

You then want to copy the public key and add that to your github.

Output your public key

cat <path-to-.ssh>/id_rsa.pub

Configure your git

Now you've got the ssh key set up, you just need to configure your git on your machine. This just includes setting the name and email address that match your github account.

git config --global user.name "<your-username>"
git config --global user.email <[email protected]>

Note that there are quotation marks around the username and not the email.

Create your first repo

If you create the repo with a README, you can simply clone the repo, rather than going through the trouble of initialising them.

Cloning the repo

git clone <ssh-repo-code>

Your first commit

To commit changes to a repository, you need to go through 3 stages. You first stage your changes (add), then commit your changes locally (commit), and then push it to the remote (push).

First step is to create a text file as an example.

Add the file to the staging area

git add file-name.txt

Alternatively, add everything in the current directory

git add .

Check that all your changes are staged

git status

If the changes have been staged, the file will show in green, if not, it will be red.

Commit your changes

git commit -m "your message."

NOTE: adding a commit message is important, make sure it is informative and makes clear what was changed with the commit.

Push your changes

git push

What do I do if someone else made a change?

To get the changes somebody else has made to the repo onto your local machine, simply use

git pull

If there are conflicts here, you can stash your changes. You may also want to just reset your repository to what it is currently if there are conflicts (given you haven't contributed anything of value) using

git checkout -- .

To stash your commit use

git stash

to put the stashed changes back in, you can use

git stash apply

What do I do if I broke something?

Go into github and find the commit that you want to go back to. Copy the commit hash, now you can get everything back to this stage.

Checkout at that commit

git checkout <commit-hash> .

NOTE: Don't forget the .!! If you miss this, the HEAD will become detatched, and you will no longer be on a branch.

After doing this, you can stage, commit, and push your changes.

Committed something you want to get fix up?

To solve this problem, just make a new commit, but don't push yet!

After committing, you need to rebase. This means changing the record of your commit history. You only need to change the last commit.

git rebase -i HEAD~2

From here, just replace pick with f and then save and quit.

Because you have now diverged from the general course of the branch, you will have to force push your changes.

git push --force-with-lease

is the safer option, but equally, when working on a project on your own

git push -f

also works.

Branches

Create a new branch

git checkout -b <branch-name>

To push to the branch, you will have to set the upstream:

git push --set-upstream origin <branch-name>

To switch back to the main branch simply

git checkout <branch-name>

To list all the branches you have created

git branch

To see all of the ones (including on remote)

git branch -a

Merge the other branch in

git merge <other-branch>