Version Control

ITEC 3870 Software Development II,
Anca Doloc-Mihu and Cengiz Günay

(License: CC BY-SA 4.0)

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Why Version Control?

• It’s a must in today’s computing industry
  • Mt. Gox, a company that don’t use VC and lost almost a billion dollars…
  • Another painful story without VC
  • challenge: find more horror stories!
• You can even version control documents, class files, financial files, …
• Also called source control, code management, concurrent versioning, revision control, …

Teamwork on the same codebase: How?

Teamwork: No control? Overwrite chaos!

Teamwork: Locking

Teamwork: Merging

Merging example

Each commit increments version

git is the program behind Github

Common usage scenario:

1. git clone gets working copy from repo
2. Make changes in local working copy
3. git add <files...> to select your changed files
4. git commit saves your changes into the version control history with a comment (Wash, rinse, and repeat step 2. Commit often!)
5. git push publishes your previous commits to remote repository (Github)
6. git pull receives latest changes from repo to sync

Useful commands: Investigating the past

• git diff shows your changes from last repo version
• git log [filename] lists all commits, optionally those touching a filename
• git diff <commit> shows changes in version labeled as <commit>
• git checkout <commit> rewinds all files back to a version

Common issues with Git

Avoiding bloating and conflict hell:

• The .gitignore file: Add lines of file patterns to be kept out of your repo.

Git Resources

• Download
• A simple Git guide
• The Pro Git book
• Learn Git branching
• More learning tutorials

Credits

• Opening comic from Return to Zero by EEworldonline.com