Why Version Control?

• How can I keep from losing my work?
• What was that code for anyway?
• How can I go back and see what my code was like before?
• How can I undo some changes or mistakes I made?

• How can I work on the same codebase on my home machine and laptop?
• How can I maintain several different versions of my project?
• How can several people all work on the same codebase at the same time?
• Who made these changes?

Many Options

• Git
• Subversion
• Mercurial
• CVS
• RCS
• Visual Studio Team Services
  (Team Foundation Server)
• ...

Choose from Different Architectures

• Locally managed, shared filesystem
• Client-Server
• Distributed

Choose from Different Usage Models

• Check out files to work on them (locking)
• Allow simultaneous changes (then facilitate merges)

Choose Project Model

• Open Source / Free Software
• Closed Source / Proprietary / Licensing

Git

About

• Written by Linus Torvalds (for Linux kernel dev)
• Licensed under GNU GPL v.2
• Free and Open Source (free as in speech, not free as in beer)
• Fully distributed model enforces Free Software Principles
• Supports MANY workflows: from large distributed projects to centralized small teams
• REALLY popular
• NOT simple!

Why We Choose Git?

• Industry standard
• Works with all languages and project types
• Supports individual development and team based work
• Easy and free to install, runs anywhere
• Small and fast, lightweight
• Free online hosting: GitHub, Bitbucket, ...
• Easy for you to create an online Portfolio of your work

Why NOT Use Git?

• Your organization is already using something else
• You actually want centralized control
• You need compartmentalization, permission controls
• Want something easier, point and click

Theory

Images from: Pro Git

(a highly recommended e-book)

Snapshots

 

A Commit

 

3 Commits

 

Branch "Pointers"

 

Branches

 

A Commit History

 

Preparing to Merge

 

After Merge

 

Complex Workflows

Image from: Bitbucket tutorial

Example from Past Years

Graph of commit history for part of a team project

Git: Basic Process

3 States

 

Lifecycle

 

Git in Practice

Demonstration of basic workflow

First Get It

• Go to git-scm.com and install it.
• Windows: Git Bash
• Mac OS and Linux: Terminal (which by default is usually a bash shell)

Second, Get it Set Up

• Configure your Name
• and Email
• Working on 2 machines?

First-Time Git Setup

Basic Use

1. Create an empty repository
2.          some files to the working directory
3. Stage one or more files
4. Make a commit
5. Edit a file and make another commit
6. View commit graph and history

Thoughtfully assemble a commit

Ultimately a commit will mean something for the project

• How to un-stage files

Viewing work from the past

• Checkout
• Show
• Diff

Removing files

• Removing from the directory, vs.
• Removing from the repository

Lots of Useful Commands

• Go back to a previous version of a file
• "Undo" a commit
• View differences between one commit and another
• Stash in-progress work
• ...

Remotes (Remote hosting)

• GitHub
• Bitbucket
• GitLab
• ... your own server

What they do

Git in Practice

Using remotes

Start with a remote repo

• Create a repo on GitHub
• Clone it
• Make local commits
• Push local changes to the remote

Start with a local repo

• Create a repo on GitHub
• Push local repo and all history to remote

A Few Tips

• Always keep in mind the commit graph
• Don't just type in a command and execute it -- think carefully first
• Run git status a ton
• Always write useful commit messages -- explain to yourself and others what the changes in the commit represent
• Learn to use Git from the command line first before trying to use a GUI for Git
• Ask for help

Where to go from here?

• Practice the correct workflow until it is second nature
• There will always be more to learn -- Git is powerful and complicated
• When in need, search for what you need to do (but be careful)
• Master using it yourself before joining a project with others
• Use it for all your projects!