Git Basics: Repositories, Commits & History

Required tools

• Git (2.x or newer)
• A terminal (or Git Bash on Windows) (any current version)

Setup

1. Open a terminal.
2. Create a dedicated, disposable practice folder: `mkdir git-basics-practice && cd git-basics-practice` — everything in this lab stays inside this one folder, so nothing outside it is ever at risk.

Project structure

git-basics-practice/
  .git/            (created by git init)
  README.md

Starter files

TODO: create this file yourself with: echo "# Git Basics Practice" > README.md
It is listed here only to show the expected final structure -- you create it
for real, in your own terminal, using the commands below.

Requirements

• The folder is a real Git repository (has a .git directory, created by `git init`).
• README.md exists and was committed in an initial commit.
• A second commit adds a line to README.md.
• `git log` shows exactly two commits, newest first.

Commands to run

• Turn the folder into a Git repository

  git init

• Create a real file with real content

  echo "# Git Basics Practice" > README.md

• Stage the new file

  git add README.md

• Commit the staged change

  git commit -m "Initial commit: add README"

• Add a second line to the file

  echo "Learning Git one commit at a time." >> README.md

• See exactly what changed before staging it

  git diff

• Stage and commit the second change

  git add README.md && git commit -m "Add description to README"

• Review the commit history

  git log

Expected behavior

`git log` prints two commits, newest first, each with its own commit hash (a string like `a1b2c3d` — an example placeholder; your actual hash will differ and that's expected, only that two distinct commits exist matters), author, date, and message: 'Add description to README' above 'Initial commit: add README'. `git diff` (run before the second commit) prints a `+` line showing exactly the sentence you added; once that change is staged and committed, `git diff` prints nothing at all.

Verify it yourself

• git log --oneline

  Expected: exactly two lines, each starting with a short commit hash followed by its message -- 'Add description to README' first (newest), then 'Initial commit: add README'

• git status

  Expected: prints 'nothing to commit, working tree clean' -- confirming every change was committed

• cat README.md

  Expected: prints both lines you added, in the order you added them

Troubleshooting

• `fatal: not a git repository` — You ran a git command outside git-basics-practice, or before `git init` succeeded -- confirm your location with `pwd` and that `git init` ran first.
• `git commit` opens a text editor instead of committing — You omitted `-m "message"` -- git commit needs either -m with a quoted message, or it opens your default editor to write one. Save and close that editor, or re-run the command with -m.
• Unsure whether a command here affects anything outside this folder — Every command in this lab only touches git-basics-practice/ and the hidden .git/ folder inside it -- nothing outside this one folder is ever read, created, or changed.

Extension challenge

Run `git log -p` (instead of plain `git log`) to see the full diff embedded in each commit's log entry -- notice it's the same information `git diff` showed you before committing, now permanently attached to the commit it belongs to.