CIS241

System-Level Programming and Utilities

git (intro)

Erik Fredericks, frederer@gvsu.edu
Fall 2025

Based on material provided by Erin Carrier, Austin Ferguson, and Katherine Bowers

How do you share files?

Or backup/transfer files?

Or manage a group project?

What are some issues with those?

• How do you merge?
• Multiple people editing at once?
• File history?
• Integrate into workflow?
• Corruption? Accidental deletion? Lose a USB drive?

Source control!

Common options:

• git
• subversion

Version control systems

Software that tracks all changes to a repository of files

Benefits:

• Full history
  • Rollbacks, traceability
• Working concurrently
• Merging
• Files never fully deleted

Distributed version control systems

• Each user has a local copy of all files
  • Including full history!
• Allows for working offline
• In theory, should make merging easier

Common version control systems

Distributed

• git
• mercurial

Centralized

• subversion
• perforce

Wot about GitHub?

git -- local

• software
• handles version control
• operates locally

GitHub -- remote

• Website/server
• Stores git repositories
• Additional features
  • Public sites
  • GitHub Actions

Touch of history on git

git:

• The most widely used source code management tool: 42.9% of professional software developers use it as their primary source control system.

  • 90% respondents say they use Git (2021 StackOverflow survey)

• Developed by Linus Torvalds in 2005 for use developing the Linux kernel

• GitHub was developed in 2008, and provides free (and paid) Git repository hosting

  • Currently owned by none other than Microsoft!

Personal notes

git is complicated

You will mess things up / break things

• I still do
• Most mistakes are recoverable
• Learn how to recover things!

Don't worry too much about the details

• Get comfortable with the big picture
• Look things up when you need (or are curious)

The process

git: repositories

Git repositories contain:

• A set of commit objects, and
• A set of references to commit objects (heads)

Git repositories are stored:

• In a .git sub-directory in the same directory as the project
• There is no central repository server

Git is distributed!

Where we're going

Where we're going

Today's work

1. Install git

• Probably already installed, but you never know
  • https://github.com/git-guides/install-git
  • We are not using GitHub Desktop! Terminal only!
  • To test, try git version

2. Create a GitHub account - you'll be sending me your username

3. Configure git on your machine

• git config --global user.name "Your name"
• git config --global user.email "Your email"