A workshop I ran at FSOSS 2013 introducing new users to git through a series of hands on exercises.

1. Introduction To Git Workshop
Tom Aratyn

2. Get Git
• On Matrix
•
I have accounts for you
• On Windows
•
http://msysgit.github.io
• On OS X
•
brew install git
• On Linux
•
sudo apt-get install git
• Otherwise
•
http://git-scm.com

3. About Me
Django and JavaScript Developer
Founder @ The Boulevard Platform
Engineer @ FoxyProxy
Created open source projects:
BitBucket Release Note Generator
django-email-changer
Exploit Me Suite

4. Why Git?
Git is
•
•
•
•
•
Small
Fast
Distributed
Free & Open Source
Trusted
•
•
•
Linux
Homebrew
Everyone on GitHub + Gitorious +

5. Not Just For Code
(but mainly for code)
http://government.github.com

7. About Today
What we will cover
• Creating Repos
• Checking Out
• Committing
• Basic Branching
• Basic Merging
• Pushing & Pulling
What we won't
• git reset
• Changing history
• Rebasing
• Adding/Removing
Remotes
• Partial Staging
• Fetch
• Tags

8. Making A Git Repository
Normal Repository
Bare Repository
Cloned Repository

9. A git repository with a working directory
Normal Repository

10. Normal Repository Exercise
$ git init workshop.normal.git

11. A git repo without a working directory
(this is what you want on the repo)
Bare Repository

12. Bare Repository Exercise
$ git init --bare workshop.bare.git

13. Cloned Repository
A normal repository is a copy of a remote repository and setup to
work with it.

14. Cloned Repository Exercise
$ git clone workshop.bare.git
workshop.git
$ cd workshop.git

15. Image By: Scott Chacon, Pro Git

16. Staging Files
Before a file can be added it must
be staged

17. Staging File Exercise
$ mvim index.html
$ git add index.html

18. What’s The Status Of My Files
Right Now?
$ git status
# On branch master
#
# Initial commit
#
# Changes to be committed:
#
(use "git rm --cached <file>..." to
unstage)
#
# new file:
index.html
#

19. Committing Files
Committing means that we want in the
version control system.
All staged files will be committed.

20. Commit File Exercise
$ git commit –m "My initial commit"

21. Commit File Exercise Result
Committer: Tom Aratyn <mystic@nelson.local>
Your name and email address were configured automatically based
on your username and hostname. Please check that they are accurate.
You can suppress this message by setting them explicitly:
git config --global user.name "Your Name"
git config --global user.email you@example.com
After doing this, you may fix the identity used for this commit with:
git commit --amend --reset-author
1 file changed, 0 insertions(+), 0 deletions(-)
create mode 100644 foo

22. The Log
Git keeps a log of everything you commit,
who wrote authored it, and who committed
it.

23. View The Git Log Exercise
$ git log
$ git log --graph
$ gitk

24. (Don’t worry there are better
GUIs, more on that later)

25. Why isn't your name there?

26. The Parts Of A Log
List of commits and branch pointers
A commit is made up of:
•
•
•
•
•
SHA1 id
Message
Files
Author
Committer

27. Configuring git
git is configured in two places:
~/.gitconfig
youreRepo/.git/config

28. Configuring Git Exercise
$ git config --global user.name
"Your Name"
$ git config --global user.email
you@example.com

29. Configuring Git Exercise Result
$ cat ~/.gitconfig
[user]
name = Tom Aratyn
email = "tom@aratyn.name"

30. Changing History
There are many ways to change history in
git.
We're only going to look at one way:
Amend the last commit.

31. Change The Last Commit Exercise
$ git commit --amend -m "initial
commit with an html file"
$ # has the author changed?
$ gitk

32. Author Vs. Committer
Git is made from from the ground up for
multiple developer projects (Linux).
Large projects often distinguish between the
author (who wrote the patch/code) and the
committer (who let it into the blessed
repository)

33. Update the Author Exercise
$ git commit --amend --resetauthor
# why did the screen change ?
# type in ":wq" to leave vim.

34. How To Remove A File?
What if we committed a file we no longer
need can we get rid of it?
Yes & No

35. From the current (and future) versions.
Yes, You Can Remove It

36. No, It'll Be In Past Versions
The whole point of version control is you can always recover old
files.

37. Remove A File Exercise
$ git rm index.html
$ ls
$ #Notice how the file is now gone
$ git status
$ #Notice how the file is staged
$ git commit -m "Removed
index.html"

38. Create another index.html and commit it
Practice: Adding a file

39. Branching
Fast and easy branching is git's killer
feature.
Branches let development progress on
multiple fronts separately and
simultaneously.

40. Check Your Branch Exercise
$ git branch
$ git branch –a
$ # What's the difference between
the two commands?

41. Create A Branch Exercise
$ git branch workshop-example
$ git branch
$ # what branch are you on?

42. Switch Branch Exercise
$ git checkout workshop-example
$ git branch
$ # now what branch are you on?

43. Switch To A New Branch
Immediately Exercise
$ git checkout -b fix-bug-123
$ git branch
$ gitk

44. Making A Change On A Branch
Exercise
$ # edit index.html
$ git add index.html
$ git commit -m "Added some initial
html"

45. Merging
Merging is really git's killer feature
Because branching without merging is pretty
useless
See CVS

46. Merging Process
1. Go to the branch you want to merge into
• Often the branch you branched off of.
• Usually "master" or "develop"
2. Do the merge

47. Two Three types of merges
1. Fast Forward Merge
2. Basic Merge
a. Conflicted Merge

48. Only available when the branch can be cleanly applied onto your
current branch
Fast Forward Merge

49. Fast Forward Merge Exercise
$ # (assuming you have a change on
fix-bug-123 - use gitk to check)
$ git checkout master
$ git merge fix-bug-123
$ gitk

50. Basic Merge Exercise
Prep
Add add a div on the master
branch
Change the title on the fixbug-123 branch
Recall
git checkout
git add
git commit

51. Basic Merge Exercise
$ git checkout master
$ git merge fix-bug-123
$ git log --graph --decorate --all

52. Conflicted Merge Exercise
Prep
Change the same line on
both branches
(change the class on the
same div)
Recall
git checkout
git add
git commit

53. Conflicted Merge Exercise
$
$
$
$
$
$
$
git checkout master
git merge fix-bug-123
git status
# edit index.html
git add index.html
git commit
git log --graph --decorate --all

54. Sharing Is Caring
So far everything we've done is on the same
repo but projects need to be shared.
Git lets you push your changes to others
and pull the changes others made.

55. Pushing Exercise
$ # Recall that we cloned our bare
repo
$ git push origin master
$ cd ../workshop.bare.git
$ git log

56. Pulling Exercise
Prep
1. Clone the bare repo
again
•
Call it workshop.2.git
2. Commit a change to
workshop.git
3. Push the change
Recall
git clone
git add
git commit
git push

57. Pulling Exercise
$
$
$
$
cd ../workshop.2.git
git branch
git pull
git log

58. How does pulling work?

59. Tracking Branches
A tracking branch is a local branch which
knows that updates to a remote branch
should be applied to it.

60. Tracking Branch Exercise
$ git checkout –t
remotes/origin/fix-bug-123

61. About Today
What we covered
• Creating Repos
• Checking Out
• Committing
• Basic Branching
• Basic Merging
• Pushing & Pulling
What we didn't
• git reset
• Changing history
• Rebasing
• Adding/Removing
Remotes
• Partial Staging

62. Where to next?
Learn more at from "Pro Git"
http://git-scm.com/book
Start Your Project:
Free Open Source Repos
http://github.com
Free Private Repos
http://bitbucket.org
GUI: http://SourceTreeApp.com

63. Questions?

64. A link to this presentation will be on
http://blog.tom.aratyn.name
@themystic
tom@aratyn.name (I can email it to you)
Thank You!