This document provides an overview of Git, including: 1. Git is an open source distributed version control system that allows for distributed workflows where each clone is a full backup. 2. Basic Git commands include configuring user information, cloning repositories, ignoring files, adding and committing changes, branching, tagging, and undoing actions. 3. A typical Git workflow involves writing code, staging changes, reviewing changes, committing changes locally, and pushing changes to a remote repository. It also covers merging, resolving conflicts, and rolling back if needed.

1. Git session
Hannes Tack

2. Overview
1. What is git?
2. Basic git
3. Workflow
4. Tips and tricks

3. What is git?

4. What is git?
Open source distributed version control system

5. Distributed
• Everything is local
– Fast
– Every clone is a backup
– Work offline

6. Basic git

7. Installing Git
• Download from http://gitscm.com/downloads
• Launch the installer
• Or Xcode, homebrew, …

8. Configuring Git
• $ git config --global user.name 'Hannes Tack‟
• $ git config –global user.email
„hannes@dropsolid.com‟

9. Clone a repo

10. Clone a repo
• Clone an existing repo or create a new one:
– $ git clone user@host:repo

11. .gitignore

12. .gitignore
• What?
– Makes git ignore files / directories
– Repo specific or global
– Drupal example of a .gitignore file:
http://drupalcode.org/project/drupal.git/blob/HEAD:
/example.gitignore

13. .gitignore
# Ignore configuration files that may contain sensitive information
*/sites/*/settings*.php
# Ignore paths that contain user-generated content.
*/sites/*files
*/sites/*/private
# Ignore editor specific files
Drupal.sublime-projectcompletions
*.sublime-project
*.sublime-workspace
# Ignore OS specific files
.DS_Store

14. global .gitignore
• Create any file:
- $vi ~/.gitignore_global
• Add paths to be ignored.
- Example: https://gist.github.com/4321950
• Use as global gitignore file:
Git config –global core.excludesfile
~/.gitignore_global

15. local .gitignore
• Create a .gitignore file:
- $vi ~/your_project/.gitignore
• Place it anywhere in your repo
• Add paths to be ignored, relative to the location of
the file.

16. A Basic Workflow

17. A basic workflow
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Write code
Stage your changes
Review your changes
Commit your changes
Push your changes

18. A basic workflow
•
•
•
•
•
Write code
Stage your changes
Review your changes
Commit your changes
Push your changes

19. A basic workflow

20. A basic workflow
Git diff
• Git diff shows what you‟ve changed
• $ git diff <filename>

21. A basic workflow

22. A basic workflow
•
•
•
•
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Write code
Stage your changes
Review your changes
Commit your changes
Push your changes

23. A basic workflow

24. A basic workflow

25. A basic workflow

26. A basic workflow

27. A basic workflow

28. Git add

29. A basic workflow

30. A basic workflow

31. A basic workflow

32. A basic workflow
Staged files
• git diff --staged shows the changes that are
staged
• git reset HEAD <filename> removes a file
from “staging”

33. A basic workflow
•
•
•
•
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Write code
Stage your changes
Review your changes
Commit your changes
Push your changes

34. Git commit

35. A basic workflow

36. A basic workflow

37. A basic workflow
Git commit
• Changes are committed to local repo
• Others won‟t see these changes yet
• Commit message is required
• And should look like „Issue #123: describe what
you changed.‟

38. A basic workflow
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•
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Write code
Stage your changes
Review your changes
Commit your changes
Push your changes

39. Git push

40. A basic workflow

41. A basic workflow

42. A basic workflow

43. Merging

44. A basic workflow
• Remote branch contains commit(s) that are not
present in your local branch.
• Get those commits first by merging, then push your
commits.

45. A basic workflow
Git pull

46. A basic workflow
Git push

47. A basic workflow
Git pull

48. A basic workflow
Git pull

49. A basic workflow
Git pull

50. A basic workflow
Git pull

51. A basic workflow
Git pull

52. A basic workflow
Git pull

53. A basic workflow
Fix code manually

54. A basic workflow
Fix conflict UI

55. A basic workflow
Fix conflict UI

56. A basic workflow
Push merged code

57. Git log

58. Git log
- View the latest 10 log messages
- $ git log -n 10

59. Git log
- Show nicer log:
- $ git log --oneline -n 20

60. Git log
- Search log messages content:
$ git log --grep=Breadcrumb

61. Git log
- Search log messages content:
$ git log --grep=Breadcrumb

62. Git log
- Search commit content:
$ git log -S "Implements hook_views_data" –oneline

63. Git log
- Show commit content: $ git show de25c94

64. Undoing things

65. Git checkout

66. Git checkout

67. Git checkout
• Throw away changes: $ git checkout index.html
• Restores your working tree to the last version
committed to git.
• Use git checkout to throw away changes that have
not been added and committed.
• Use carefully.

68. Git checkout

69. Git reset

70. Git reset

71. Git reset
• Keep your code changes, remove file from
the index: $ git reset HEAD index.html
• Restores your index to the last version
known to git.

72. Git reset

73. Git reset --hard

74. Git reset --hard
• Resets working tree and index to a specific
commit.
• $ git reset --hard 5497461
• Reset a branch to the origin branch: $ git
reset --hard origin/master
• Use carefully.

75. Git revert

76. Git revert
• Undo a specific commit: $ git revert
5497461
• Creates a new commit that removes the
specified commit.

77. Git revert

78. Branching

79. Branching
- List local branches:
$ git branch

80. Branching
- List all branches: $ git branch -a

81. Branching
- Create a new branch: $ git branch issue-123
- Switch to that branch: $ git checkout issue123
- Or create and switch to a branch: $ git
checkout -b issue-123
- Push branch to origin: $ git push origin
issue-123

82. Branching
- Use a remote branch: $ git checkout -t
origin/issue-11699

83. Branching
• Delete a local branch that is fully merged: $
git branch -d branch_name
• Force delete a local branch: $ git branch -D
branch_name
• Delete a remote branch: $ git push origin -delete :branch_name
• Completely remove a branch: $ git push
origin --delete :branch_name $ git branch -D
branch_name

84. Tagging

85. Tagging
• Create tag: $ git tag sporting-beta-1 -a -m
'Sporting beta 1 release.'
• Push tag: $ git push --tags
• List tags: $ git tag

86. Tagging
• Move a tag: $ git tag -f sporting-beta-1
• Delete a tag: $ git tag -d sporting-beta-1 $
git push origin :sporting-beta-1

87. Patching

88. Patching
• $ git diff > [project_name][short_description]-[issue-number][comment-number].patch
• Add the patch file to the root of the module
you patched.

89. Tips & tricks

90. Git stash

91. Git stash
• Store code changes without committing
them.
• Handy when you urgently need to switch
branches.
• Stash your code changes: $ git stash
• List all available stashes: $ git stash list
• Most recent stash is shown on top

92. Git stash
• Apply a stash: $ git stash apply stash@{0}

93. Git stash

94. Git aliases

95. Git bisect
• Shortcuts
• Define aliases in .gitconfig file.
• Ex: ~/.gitconfig

96. Git aliases

97. Git aliases

98. Git bisect

99. Git bisect
• Find out in when something broke
• First, find a commit when everything was
working
• Find a commit where things are not working.
• Go to the root of the repository
• $ git bisect start $ git bisect good fd0a623 $
git bisect bad 256d85

100. Git bisect
• Refresh the page and see if the bug is there
• $ git bisect good/git bisect bad
• Repeat until git tells you the commit that
broke it

101. Resources

102. Resources
• Pro git book: http://git-scm.com/book
• Git bisect tutorial: http://webchick.net/node/99

103. Questions?