# git pull & push & diff

## Goal
Work with a remote, push and pull changes, and compare differences.

## Set Up a Local "Remote" (Offline-Friendly)
We'll simulate a remote using a bare repository.
```bash
cd ~/lab-git-essentials
git init --bare remote.git
```

## Connect Your Repo to the Remote
```bash
cd ~/lab-git-essentials/my-first-repo
git remote add origin file://$HOME/lab-git-essentials/remote.git
git remote -v
```

## Push Your Main Branch
```bash
git checkout main
git push -u origin main
```

## Simulate a Collaborator and Pull
Create a second local clone, make a change, push it, then pull it back.
```bash
cd ~/lab-git-essentials
git clone file://$HOME/lab-git-essentials/remote.git collaborator
cd collaborator
echo "Edit from collaborator" >> collab.txt
git add collab.txt
git commit -m "Collaborator adds a file"
git push origin HEAD:main

# Back in your original repo, pull the change
cd ~/lab-git-essentials/my-first-repo
git pull
ls
```

## View Differences
```bash
# Compare working tree vs last commit
echo "temp edit" >> notes.txt
git diff

# Compare staged vs last commit
git add notes.txt
git diff --staged

# Compare two commits (use your own SHAs)
git log --oneline -n 2
git diff HEAD~1 HEAD
```

## (Optional) Use a Hosted Remote
If you have GitHub/GitLab:
```bash
git remote set-url origin https://github.com/<you>/<repo>.git
git push -u origin main
git pull --rebase
```

## Outcome
You can push to and pull from a remote, and use `git diff` to compare changes.