Git & GitHub Cheatsheet

version control. the thing that saves your ass.

what is git

git tracks changes in your files over time.
think of it like save states in a video game — you can go back to any point.

github is just a website that hosts your git repos online.

your laptop  →  git  →  github
(local)          (tool)    (remote)

the mental model

working directory   →   staging area   →   repository
(files you edit)        (what you're         (saved history)
                         about to save)

    git add                git commit

setup (do this once)

git config --global user.name "yourname"
git config --global user.email "youremail@gmail.com"

starting a repo

# start fresh
git init

# or clone existing from github
git clone git@github.com:username/reponame.git

daily workflow

# check what changed
git status

# see exact changes
git diff

# stage files
git add filename.md        # specific file
git add .                  # everything

# commit (save snapshot)
git commit -m "what you did"

# push to github
git push

# pull latest from github
git pull

commit messages

keep them short and clear:

git commit -m "add vim notes"
git commit -m "fix typo in readme"
git commit -m "update git cheatsheet"

bad:

git commit -m "stuff"
git commit -m "asdfgh"
git commit -m "changes"

branches

branches let you work on something without breaking the main stuff

# see all branches
git branch

# create new branch
git branch feature-x

# switch to it
git checkout feature-x

# shortcut — create and switch
git checkout -b feature-x

# merge back to main
git checkout main
git merge feature-x

# delete branch after merge
git branch -d feature-x

undoing things

# unstage a file
git restore --staged filename.md

# discard changes in working dir (careful — permanent)
git restore filename.md

# undo last commit but keep changes
git reset --soft HEAD~1

# see commit history
git log --oneline

remote (github)

# see remote urls
git remote -v

# add remote
git remote add origin git@github.com:username/repo.git

# change remote url
git remote set-url origin git@github.com:username/repo.git

# push for first time
git push -u origin main

# push after that
git push

ssh setup (one time)

# generate key
ssh-keygen -t ed25519 -C "youremail@gmail.com"

# copy public key
cat ~/.ssh/id_ed25519.pub

# paste it on github → settings → ssh keys

# test it
ssh -T git@github.com

common situations

i messed up my last commit message:

git commit --amend -m "correct message"

i want to see what changed between commits:

git log --oneline
git diff abc123 def456

i accidentally committed to main, want a branch:

git checkout -b new-branch
git checkout main
git reset --soft HEAD~1

pull has conflicts:

# open the conflicting file, look for:
<<<<<<< HEAD
your changes
=======
their changes
>>>>>>> main

# pick what to keep, delete the markers
# then:
git add .
git commit -m "resolve conflict"

git ignore

create .gitignore to tell git what to ignore:

nano .gitignore

node_modules/
.env
*.log
__pycache__/
.DS_Store

cheatsheet

command	what it does
`git init`	start a repo
`git status`	see what changed
`git add .`	stage everything
`git commit -m ""`	save snapshot
`git push`	upload to github
`git pull`	download from github
`git clone`	copy a repo
`git log --oneline`	see history
`git branch`	list branches
`git checkout -b`	new branch
`git merge`	merge branch
`git diff`	see changes

=^._.^= ノ  commit early, commit often