The document provides an overview of git for beginners. It discusses why distributed version control is useful, basic git commands and workflows, using git from the command line and Visual Studio Code. It also covers branching, merging, stashing and resources for learning more about git. The session aims to explain the basics of git and how it can be used from different interfaces.

1. git for the uninitiated
Paul Litwin
Fred Hutchinson Cancer Research Center
plitwin@fredhutch.org
@plitwin

2. Slides can be found here…
• http://tinyurl.com/litwin-sea-web
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3. Session Itinerary
• Why distributed version control?
• git basics
• Command line git
• Using git from VS Code
• Using git from Visual Studio
• Branching and merging
• Wrap up
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4. Why distributed version control?

5. Git is a free and open source distributed
version control system designed to handle
everything from small to very large projects
with speed and efficiency
Created by Linux creator, Linus Torvalds
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6. The name git?
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“I'm an egotistical
bastard, and I name
all my projects after
myself. First Linux,
now git.”
Linus Torvalds quote from 2007

7. Centralized Version Control
One repository using a client-server model
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8. Distributed Version Control
Many repositories using peer to peer model
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9. Comparing centralized (tfs) vs distributed (git)
Attribute Centralized
TFS, SVN, PVCS
Distributed
git, Mercurial
Repositories 1 Many
Model Client-server Peer-to-peer
Speed of common
operations
Slower Fast against local repo
Redundancy of system None; single point of
failure
Redundancy built in
Offline work More difficult Easy
Merging of changes When you check
changes in
When you sync changes
(push/pull)
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10. git Basics

11. git Basics: Getting git
• Download from: https://git-scm.com/
• Configure
– git config --global user.name “your name”
– git config --global user.email “email address”
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12. git Basics: How it works
Working
Directory
stage
Staging
Area
commit
git repo
modified staged committed
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13. Command line git

14. Using Command Line
• Windows
– use command prompt
– you may need to add git to the path (find git.exe and
add this folder to the system path)
• Control Panel|(System and Security)*|System|Advanced
System Settings|Environment Variables and select Path and
click Edit
* Windows 8/10 only
• Mac
– use terminal program
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15. Creating a local repo
• git init
– creates a local repository in current folder by
creating a hidden .git subfolder
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16. Lifecycle of Files
• git status
– displays the status of your project’s files
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17. Basic commands
• Add files to staging area
– git add
• Commit files to local repo
– git commit –m “message”
• Unstage changes
– git reset
• Check status of project files
– git status
TIP: You can create rules
which automatically ignore
certain types of files (e.g.,
DLLs, .sln, .proj) by git by
using a .gitignore file. The
ignored files will not be
tracked/added/committed
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18. Commit Versions
• Display log of commits
– git log
each commit is listed with its SHA-1 checksum which you can use to refer
to the commit using other commands
• Display log of commits with list of changes
– git log -p
• Revert to prior commit & discard history since
– git reset --hard commit
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19. Differences
• Diff between unstaged (but tracked) changes
and staged changes
– git diff
• Diff between staged and last commit
– git diff --staged
• Diff between two different commits
– git diff commit1 commit2
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20. Working with a remote repo
• git clone url folder
– makes a copy of a remote git repository from url
into the local folder
– also names the remote “origin” and sets it as
default remote
• git remote add name url
– Creates link between current repo and named
remote repo
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21. Git Hosting Services
• GitHub
– free for public, open source repos
– $ for private repos
• Bitbucket
– free for up to 5-person team private repos
• VS Online
– free for up to 5-person team private repos
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22. Exchanging changes with remote
• git pull
– downloads remote changes and merges them into
your repo
• git push
– uploads local committed changes to remote
– git push –u origin master
• pushes content to origin remote from master branch
and remembers your remote and branch settings
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23. Litwin Git for the Unitiated 23

24. Litwin Git for the Unitiated 24

25. Using git from VSCode

26. Code and git (1 of 3)
• VS Code can…
– create a local repo
– add files to staging area
– commit files
– pull/push to remote
– show diffs
– view git command history
• VS Code cannot…
– clone a repo
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27. Code and git (2 of 3)
total # of
changes
Change icons
A – added
M – modified
D – deleted
U – untracked
Commit with
message
refresh
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28. Code and git (3 of 3)
context sensitive actions when
rolling over file name
click on file name to see diff
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29. Using git from Visual Studio

30. Using git from Visual Studio 2015
• Git also works with Visual Studio 2015 (and
2013)
• Unlike VS Code, Visual Studio can clone
• One big oddity about Visual Studio and git
– There is no staging of changes
– You commit directly (equivalent to git commit -a)
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31. Working with git from Visual Studio 2015
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32. Branching and merging

33. Branching
• every git repo starts with master branch
• git branch newBranch
– creates branch named newBranch
• git checkout newBranch
– switches to branch newBranch
– changes files in working directory to new branch
• git checkout –b newestBranch
– create & switch to newestBranch branch in 1 step
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34. Merging
• Two steps
1. git checkout branchToMergeTo
2. git merge branchToMergeFrom
Any merge conflicts will need to be resolved and the resulting changes
committed
• Deleting a branch
– git branch –d branchToDelete
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35. More on branches
• git branch
– no arguments; lists all branches
• git branch --merged
– lists all branches you have merged with
• git branch --no-merged
– lists all branches you have not merged with
• git diff branch1 branch2
– shows differences between two branches
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36. Branches & remotes
• gets a little more complicated
– git fetch remote
• download all history from remote but don’t integrate
– git pull remote branch
• download & merge remote commits into local branch
– git push remote branch
• send branch commits to remote branch
Homework: Read chapter 3 (Git Branching) of
https://git-scm.com/book/en/v2 for more on branching
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37. Stashing
• git stash
– temporarily stashes away all tracked changes so you
can switch to another branch
• git stash apply
– reapplies most recently stashed changes
• git stash drop
– deletes most recently stash
• git stash pop
– reapplies most recently stashed changes and deletes
the stash
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38. Wrap Up

39. Wrap Up
• git is a distributed source control repository that
has a lot of power & a groundswell of developer
community support
• You can use git from
– command line
– VS Code
– Visual Studio
– other git GUI tools
• I’ve only scratched the surface of git
– See next slide for resources where you can learn more
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40. Resources
• Download git
– http://git-scm.com
• Various resources
– https://git-scm.com/documentation
• Free book -- Pro Git
– https://git-scm.com/book/en/v2
• Interactive tutorial
– https://try.github.io/
• Cheat sheets
– http://www.git-tower.com/blog/git-cheat-sheet/
– http://ndpsoftware.com/git-cheatsheet.html
– https://training.github.com/kit/downloads/github-git-cheat-sheet.pdf
• Git GUI tools (useful for visualizing branches)
– Source Tree: https://www.sourcetreeapp.com/
– GitHub Desktop: https://desktop.github.com/
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41. Slides can be found here…
• http://tinyurl.com/litwin-sea-web
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Thank you!