Managing git

I appreciate git’s power, but I still find it unnecessarily complicated. I am not going to whine or complain here about that. Instead, I decided to outline a few steps about setting up keys and some basic commands. I am using GitHub as an example.

Setting up keys

Click on your profile picture, then go: Settings → SSH and GPG keys → New SSH key. For detailed instructions click on “Check our guide to generating SSH keys.” Open a terminal, then:

Generate an ed25519 key:

ssh-keygen -t ed25519 -C "myemail@email.com"

you will be prompted the following, and normally you go with the default:

Enter file in which to save the key (/home/<user>/.ssh/id_ed25519):
Your identification has been saved in /home/<user>/.ssh/id_ed25519
Your public key has been saved in /home/<user>/.ssh/id_ed25519.pub

Analogously, for the legacy method (that’s what I have used):

ssh-keygen -t rsa -b 4096 -C "myemail@email.com"

Enter file in which to save the key (/home/<user>/.ssh/id_rsa):
Your identification has been saved in /home/<user>/.ssh/id_rsa
Your public key has been saved in /home/<user>/.ssh/id_rsa.pub

Tell ssh about the key:

ssh-add /home/<user>/.ssh/id_ed25519

-or-

ssh-add /home/<user>/.ssh/id_rsa

Make sure you have a ~/.ssh/config file with the following contents:

# Default account
Host github.com
   HostName github.com
   User git
   # Depending on what you used:
   IdentityFile ~/.ssh/id_ed25519
   # IdentityFile ~/.ssh/id_rsa

Open id_ed25519.pub or id_rsa.pub and paste the contents (key) at GitHub in SSH keys / Add new field. Set a title to your liking.

You can have several users on the same machine e.g a “work” user and a “hobby” user, each managing a different git account. When generating the key, specify a custom file name:

/home/<user>/.ssh/id_ed25519_custom

Tell ssh about the key:

ssh-add /home/<user>/.ssh/id_ed25519_custom

Add the following to ~/.ssh/config

# Custom account
Host github.com-custom
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_ed25519_custom

Using git

Set up details (globally)

git config --global user.name "Firstname Secondname"
git config --global user.email myemail@email.com
git config --global core.editor nano
git config --global init.defaultBranch main

To start a new repo locally, initiate in an empty folder, create the empty repo online in the browser (just create it, without a README), and specify origin:

git init
git remote add origin git@github.com:UserName/newRepo

To clone an online repo locally:

git clone https://github.com/UserName/repoName

Commits and push

# tell git to track all new files (if any):
git add *

# or, tell git to add only one changed file (or folder):
git add README.md

# commit all changes (you'll be promped for a message):
git commit -a

# or, commit just one changed file/folder (-m: message):
git commit README.md -m "README.md: Added"

# push commit online:
git push -u origin main

Working with branches

# make a branch (“devel”) and switch to it:
git branch devel
git checkout devel

# push changes to branch
git push -u origin devel

# switch back to main and merge devel to main
git checkout main
git merge devel

# check what branches you have and where you are
git branch

# delete a branch "devel" (careful!!):
git branch -d devel

# push the delete action:
git push -d origin devel

If you have several users managing different repos, things may get complicated, because you need to specify which user does the commits. You need to remove this, because the default is git@github.com:

# remove origin
git remote rm origin

# then add the custom one
git remote add origin git@github.com-custom:UserName/newRepo