This was a 50 minute talk I gave at CPOSC (http://cposc.org) in October 2012.

1. Why We Love Git
Jason May
Wednesday, June 26, 13

2. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

3. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

4. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

5. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

6. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

7. Why We Love Git
We can expressively track
content among multiple
endpoints.
Wednesday, June 26, 13

8. Commits are a form of documentation.
Wednesday, June 26, 13

9. Checkout states
“HEAD”
Wednesday, June 26, 13

10. Checkout states
Commit
A
Commit
B
HEAD
Wednesday, June 26, 13

11. Checkout states
“HEAD”
The working tree
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12. Checkout states
$ touch README.txt
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13. Checkout states
$ touch README.txt
$ git status --short
?? README.txt
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14. Checkout states
Commit
A
Commit
B
HEAD
Working tree
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15. Checkout states
Working tree HEAD
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16. Checkout states
Working tree HEAD
? ? ?
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17. Checkout states
$ git add README.txt
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18. Checkout states
$ git add README.txt
$ git status --short
A README.txt
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19. Checkout states
The Index!
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20. Checkout states
Commit
A
Commit
B
HEAD
Working tree
Wednesday, June 26, 13

21. Checkout states
Commit
A
Commit
B
HEAD
Wednesday, June 26, 13

22. Checkout states
Commit
A
Commit
B
HEAD
Wednesday, June 26, 13

23. Checkout states
Commit
A
Commit
B
HEAD
Index
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24. Checkout states
Working tree HEAD
? ? ?
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25. Checkout states
Working tree HEADIndex
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26. Checkout states
Working tree HEADIndex
? ? ?
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27. Checkout states
$ git commit -m ‘Add README.txt’
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28. Checkout states
$ git commit
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29. Checkout states
Commit
A
Commit
B
HEAD
Index
README.txt
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30. Checkout states
Commit
A
Commit
B
Index *commit*
HEAD
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31. Checkout states
Commit
A
Commit
B
Index
HEAD
Wednesday, June 26, 13

32. Checkout states
Commit
A
Commit
B
Index
Commit
C
HEAD
Wednesday, June 26, 13

33. Checkout states
Commit
A
Commit
B
Index
Commit
C
HEAD
Wednesday, June 26, 13

34. Checkout states
Commit
A
Commit
B
Commit
C
HEAD
Wednesday, June 26, 13

35. The concept of a ref
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36. Checkout states
Commit
A
Commit
B
Commit
C
HEAD
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37. Checkout states
42ae0e0
8e0c855
bc65d74
f96bb37
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38. Checkout states
42ae0e0
8e0c855
bc65d74
f96bb37 HEAD
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39. HEAD
What is a ref?
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40. my-branch
What is a ref?
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41. origin/my-branch
What is a ref?
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42. What is a ref?
$ git reset HEAD^
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43. What is a ref?
42ae0e0
8e0c855
bc65d74
f96bb37 HEAD
(reset)
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44. What is a ref?
42ae0e0
8e0c855
bc65d74
f96bb37
HEAD
(reset)
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45. Remotes
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46. Interacting with a
Remote
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47. Interacting with a
Remote
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48. Interacting with a
Cloning
Remote
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49. Interacting with a
Local Checkout
Cloning
Remote
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50. Interacting with a
$ git clone git://HOST/repo.git
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51. Interacting with a
$ git clone ./dir/repo.git
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52. Interacting with a
$ git clone user@host:dir/repo.git
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53. Interacting with a
Pulling
Local Checkout Remote
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54. Interacting with a
Pulling
Local Checkout Remote
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55. Interacting with a
$ git pull origin master
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56. git-fetch
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57. git-fetch
git-merge
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58. master is local!
origin/master is also local!
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59. Interacting with a
$ git pull --rebase origin master
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60. git-fetch
git-rebase
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61. Checkout states
42ae0e0
8e0c855
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62. Checkout states
42ae0e0
8e0c855
“base”
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63. Checkout states
42ae0e0
8e0c855
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64. Checkout states
42ae0e0
8e0c855
f96bb37
Wednesday, June 26, 13

65. Checkout states
42ae0e0
8e0c855
f96bb37
Wednesday, June 26, 13

66. Checkout states
42ae0e0
8e0c855
bc65d74
f96bb37
Wednesday, June 26, 13

67. Checkout states
42ae0e0
8e0c855
bc65d74
f96bb37
new “base”
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68. Checkout states
42ae0e0
8e0c855
bc65d74
f96bb37
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69. Interacting with a
$ git push origin master
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70. Decentralization is great, but it is still good to create a
structure of authority.
Workflow
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71. Workflow
gitolite
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72. Workflow
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73. git-flow
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74. git-flow
features
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75. git-flow
$ git flow feature start more-dots
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76. F
E
D
A
B
C
develop
feature/more-dots
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77. git-flow
releases
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78. git-flow
$ git flow release start 2.0
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79. F
E
D
A
develop
release/2.0
B
C
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80. git-flow
hotfixes
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81. git-flow
$ git flow hotfix start 2.0.1
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82. F
E
D
A
develop
hotfix/2.0.1
B
CF
E
D
A
master
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83. git-flow
support
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84. git-flow
$ git flow support start 3.0
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85. git’s philosophy
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86. Immutable branches
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87. Rewriting history
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88. Is history ever lost?
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89. The ref log
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90. Example: git commit --
amend
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91. Git amend
42ae0e0
8e0c855
bc65d74
f96bb37
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92. Git amend
42ae0e0
8e0c855
bc65d74
f96bb37 fd0g830
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93. Git amend
42ae0e0
8e0c855
bc65d74
f96bb37 fd0g830
shows up in ref-
log
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94. Git amend
42ae0e0
8e0c855
bc65d74
f96bb37 fd0g830
shows up in ref-
log
new HEAD
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95. When is this okay?
Hasn’t been pushed upstream
Pushed upstream but nobody has pulled*
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96. Summary
Git history is very readable
Constructing commits is flexible
Organizing commits is flexible
Virtually nothing is lost
Wednesday, June 26, 13