Git Beyond the Basics with John Bohn One thing that makes git a great version control systems is its low barrier to entry, but there's so much more to learn. We'll start with a very brief intro to git and quickly move onto some more fun and advanced topics such as recovering lost commits, rebasing, bisecting, bookmarking and more. Come learn some valuable tips and tricks that are sure to same you time and headaches. A second generation developer working at OpenSky, John Bohn is an open source contributor and advocate of anything that gets the job done better and faster.

1. git beyond
the
basics
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2. John Bohn
@jjbohn
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3. Developer at OpenSky
curated social commerce
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4. what
is git
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5. git is fast and lightweight
free/open source
distributed
crazy simple
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6. init
branch
add
commit
merge
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7. Almost any VCS works does this
(more or less)
What is special about git?
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8. Interactivity
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9. git add --patch
git add --interactive
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10. Arduino Example
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11. Change Blink
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12. Change Blink
- Two logical changes
- Don’t want to bother undoing one
- Can’t git add . or git add [file]
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13. git add --patch
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14. git add --patch
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15. git add --patch
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16. git add --patch
Commit the change
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17. git add --patch
Stage other changes
Diff is now empty (everything is staged or commited)
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18. git stash
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19. is super boring
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20. until you throw
some flags at it...
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21. My Favorites
git stash --no-keep-index
git stash --keep-index
git stash --include-untracked
git stash --patch
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22. Finding these
commands is just
a matter of
digging
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23. git anything --help
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24. git reset
is not
git revert
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25. git reset --soft [sha]
git reset --hard [sha]
git reset --mixed [sha]
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26. You can also:
git reset --patch
(but not with those modes)
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27. Bisecting
aka: Finding a commit
that screwed things up.
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28. Bisecting
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29. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
6 Commits - One Bug
We know that 7b35b is good
We know that cfc332 is bad
But we have no idea where the bug was introduced
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30. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good bad
Tell git what is known good and bad
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31. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good bad
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32. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good good bad
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33. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good good good bad
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34. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good good good bad
2ab1f is most likely good because the commit after it is
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35. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good good good bad bad
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36. Bisecting
7b35b 2ab1f 9680d 91296 c6d43 cfc332
good good good bad bad bad
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37. Recovering lost commits
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38. git reflog
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39. git reflog
Technically shows any action where the tip of a branch
is modified
git reflog --all
shows stashes, bisects, etc.
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40. Recovery
Let’s say I reset --hard and wiped out the commit that
changed my LED to pin 10
Use combination of reflog and cherry-pick to get it back
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41. Recovery
Found it! 3ecdba3
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42. Recovery
Double check that 3ecdba3 is really the commit we want
git diff 3ecdba3^.. 3ecdba3
Shows me the difference between the commit I want
to cherry pick and the commit prior.
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43. git cherry-pick
Now cherry pick 3ecdba3 into our working tree
Note: the sha has changed because this commit now has
a different parent than it did when it was recorded into
the reflog
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44. Recovery
Checkout the reflog again to see the cherry-pick
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45. Interactive Rebasing
Changing the past
one commit at a
time
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46. git rebase -i [commit]
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47. git rebase -i [commit]
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48. git rebase -i [commit]
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49. git rebase -i [commit]
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50. Interactive rebase
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51. git internals
The plumbing and the porcelain
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52. git internals
git stores snapshots, not differences
Storing differences is slow and inflexible
CVS/Subversion git
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53. git internals
git stores snapshots, not differences
Storing differences is slow and inflexible
CVS/Subversion git
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54. git internals
What does a commit look like?
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55. git internals
Let’s investigate a repo
Sorry for the bad “investigation” image ;-)
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56. Thanks!
Come work with me at OpenSky!
We’re Hiring
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