Mastering git
Lesson 2
Irina Gulina Tomas Tomecek
Questions
Recap Lab 1
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Today’s class
▸ Slides 41 and 52 from Lecture #1
･ Create a local repository
･ Make it a version controlled
･ Create a file with some content. What will show git status?
･ Notify git about that new file
･ Save your changes in a repository
▸ Share your local repository publicly
･ Create an origin
･ How to connect your origin with a local? What protocol? Why?
･ Sync origin and local. How?
Lab 1: Local => Origin
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Today’s class
▸ Create an origin repository in UI
▸ Create a local version of it. How?
▸ Difference between init and clone
Lab 1: Origin => Local
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Questions
Any questions or
suggestions?
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Questions
We have questions!
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Today’s class
▸ What is a staging area?
▸ In what 4 states can a file be when running git status?
▸ What does git commit do?
Questions
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Today’s class
▸ How does branching work in git
▸ Best practices for branching
▸ Git tags: how to use them and what’s their use case?
▸ Stash: put your current work on a shelf and restore it later.
▸ Labs: branching!!
▸ Homework 1 assignment
Today’s class
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Git Branching
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Branching
More info: https://git-scm.com/book/en/v2/Git-Branching-Branches-in-a-Nutshell
What branch is?
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main
Why branching
▸ Work in parallel
▸ Keep main branch free from questionable code
▸ Experiment easily
Why do we need branches?
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First branch
Git version 2.41.0
What is the first branch?
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Branching
● Default branch
● Create a new branch
● List branches
● Switch branches
● Work in parallel on different branches
● Merge branches
● Delete a branch
● Rename a branch
● *Stash changes and tags
● Push and pull a branch to a remote server
Branching operations
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Create a branch
$ git branch testing
Create a branch
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main
List branches
$ git branch <--list>
$ git branch -v
$ git branch -vv
$ git branch -a
List branches
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main
Switch branches
$ git switch testing
Switch branches
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Switch branches
$ git switch -c testing
Create and switch
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Switch vs Checkout
$ git switch = git checkout
$ git switch -c = git checkout -b
git-checkout - Switch branches or restore working tree files
git-restore - Restore working tree files
git-switch - Switch branches
Switch vs Checkout
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Head
HEAD
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.git/refs/heads/
.git/HEAD
Work in parallel
$ touch file.txt
$ git commit -a -m “add file.txt”
Work in parallel
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Work in parallel
$ git switch main
Work in parallel
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Work in parallel
$ touch file2.txt
$ git commit -a -m “add file2.txt”
Work in parallel
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Rename branches
$ git branch -m <new_name>
Rename a branch
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Merge branches
$ git switch main
$ git status
$ git fetch
$ git pull
$ git merge hotfix
Merge branches
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main
Merge branches
$ git switch main
$ git status
$ git fetch
$ git pull
$ git merge hotfix
Merge branches (ff)
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main
Merge branches
$ git switch iss53
$ vi index.html
$ git commit a -m “fix link [issue 53]”
Merge branches
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main
Merge branches
$ git switch main
$ git status
$ git merge iss53
Merge branches (merge commit)
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main
Merge branches
Merge branches
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Delete branches
$ git branch -d testing
$ git branch -D testing
$ git push origin --delete testing
$ git push origin :testing
Delete a branch
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Stash
Stash
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Default branch
A special “branch”
git has high-level operations to work with it
Handy to put things on side
git stash
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Default branch
git stash list
git stash show
git stash [push]
git stash apply vs. git stash pop
stash@{2}
git log stash
git stash (commands)
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THE END
Tags
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Default branch
Points to a commit and doesn’t change as you commit more
Used mainly to track releases and deployments
Lightweight vs. Annotated
Push/pull tags
git tag
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THE END
Test your knowledge now!
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Default branch
▸ Fork this repo and clone it: https://gitlab.com/redhat/research/mastering-git/
▸ Create a branch
▸ Switch to that branch
▸ List branches
▸ Create another branch
▸ Switch to it and create a commit
▸ Switch to the previous branch and merge the last branch into it
▸ Delete the previous branch
▸ Special task: create a new branch and merge it into the first branch in a way so it’s not
fast-forward: there is a merge commit
Task
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THE END
Questions?
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HW
https://gitlab.com/redhat/research/mastering-git#class-2-homework
All homework info will be in README.md
Class 2 homework
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Bonus Task
Make a contribution to an Open Source project.
▸ Not an University Project
▸ Not owned by you
▸ MR/PR doesn’t need to be merged by the Task/Course deadline
▸ A change can be of any content (not necessary code, it can be docs for example), but it must
be meaningful, positive
▸ See details in “Mastering git” Readme
First Timers Only
10 C++ open source projects welcoming contributions
Contributions-welcome topics on GitHub
Hacktoberfest - 10th anniversary. Check on participation info
Bonus Task
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THE END
THANK YOU!
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