Git is a distributed version control system designed to handle small and large projects with speed and efficiency. It allows for fast branching and merging. Git keeps an archive of all code changes over time, allows comparing changes and reverting to old releases, and provides accountability. The basic Git workflow involves modifying files in the working directory, staging files to add a snapshot to the staging area, and committing files which permanently stores the snapshot. Remote branches allow collaborating on code by fetching and pushing changes between local and remote repositories. Common commands include pull, push, commit, branch, tag, merge, and checkout.

1. Git
An intro to Git Source Control Management

2. What is Git?
Distributed version control system
Linus Torvalds - to track linux kernel development
Free and open source
Designed to handle small/large projects with speed and efficiency
Fast branching and merging

3. Why source control?
Faster development
Archive of all code changes over time
Compare changes and revert to old release
Accountability
Conserve disk space
Good for you

4. Distributed vs Centralized

5. The Basics

6. Installing git
• To initialize git directory
• $ git init
• Start version controlling existing files
• $ git add *.php *.inc *.html *.tpl
• $ git commit -m ‘Initial project version’
• Cloning an existing repository
• $ git clone ssh://clickindia@192.168.0.77/home/clickindia/public_html/clickindia

7. Basic git workflow
• You modify files in your working directory
• You stage files adding snapshot of them to staging area
• You do a commit which takes the files in staging area and
stores the snapshot permanently

8. Changes in repository
To check status of your files
Modifying files
Tracking new files
Removing files
Staging modified files
Committing files
Ignoring files

9. Example of gitignore
$ cat .gitignore
*.[oa]
*~
*.a # no .a files
!lib.a # but do track lib.a, even though you're ignoring .a files above
/TODO # only ignore the root TODO file, not subdir/TODO
build/ # ignore all files in the build/ directory
doc/*.txt # ignore doc/notes.txt, but not doc/server/arch.txt

10. Viewing staged and
unstaged changes
git status
git diff (Compares working directory with staging area)
git diff --staged
git diff HEAD
git diff v1.0 v1.1
git diff master adposting

11. Branching
$ git add README test.rb LICENSE
$ git commit -m 'initial commit of my project'
Created on commit Created on add

12. Branching

13. Branching

14. Creating new branch
$ git branch testing

15. Current branch

16. Switching branch
$ git checkout testing

17. Significance of branch
$ vim test.php
$ git commit -am “made a change”

18. Significance of branch
$ git checkout master

19. Significance of branch
$ vim test.php
$ git commit -am “made a change”

20. Basic branching and merging
• Create a new feature branch
• Do some work in that branch
Critical issue in production
• Revert back to production branch
• Create a new branch to add the hotfix
• After testing, merge the hotfix branch and push to
production
• Switch back to your original issue and continue

21. Basic branching and merging
$ git checkout -b iss53
Switched to a new branch "iss53"

22. Basic branching and merging
$ vi index.html
$ git commit -a -m 'added a new footer [issue 53]'

23. Basic branching and merging
Issue in production
$ git checkout master
Switched to branch “master”
$ git checkout -b ‘hotfix’
Switched to a new branch “hotfix”
$ vim index.html
$ git commit -am ‘fixed a broken email address’
[hotfix]: created 3a0874c: "fixed the broken email address"
1 files changed, 0 insertions(+), 1 deletions(-)

24. Basic branching and merging
$ git checkout master
$ git merge --no-ff hotfix
Updating f42c576..3a0874c
README | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)
$ git branch -d hotfix
Deleted branch hotfix (3a0874c).

25. Basic branching and merging
$ git checkout iss53
Switched to branch "iss53"
$ vim index.html
$ git commit -a -m 'finished the new footer [issue 53]'
[iss53]: created ad82d7a: "finished the new footer [issue 53]"
1 files changed, 1 insertions(+), 0 deletions(-)

26. Basic branching and merging
$ git checkout master
$ git merge iss53
Merge made by recursive.
README | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

27. Basic branching and merging
$ git branch -d iss53

28. Branch management
$ git branch # Shows all the active branches
$ git branch -v # Shows last commit on each branch
$ git branch --merged # Shows which branches are merged with the branch you are on
$ git branch --no-merged # Shows all branches that contain work you haven’t merged
$ git branch -d testing # To delete a branch. Will fail if the branch is not yet merged

29. Remote branches
• Remote branches are references to the state
of branches on your remote repositories

30. Remote branches

31. Remote branches
$ git fetch origin # Fetches any data you don’t have from remote ‘origin’ repository
$ git fetch origin master # Fetches data only from ‘master’ branch
$ git pull origin # Fetches any data you don’t have and merges it with local branch
$ git pull origin master # Fetches data from master and merges it with local master branch
$ git push origin develop # Pushes data from local ‘develop’ branch to remote ‘develop’ branch
$ git push origin develop:release # Pushes data from local ‘develop’ branch to remote ‘release’ branch
git fetch origin

32. Remotes
$ git remote
Origin
$ git remote -v
Origin ssh://clickindia@192.168.0.77/home/clickindia/public_html/clickindia
$ git remote add test ssh://clickindia@test.clickindia.com/home/clickindia/public_html....
$ git remote rm origin

33. Gist of git

34. Git branching model

35. How will we work?
pull
master master master
pull
develop
push release
Development Test server Production
192.168.0.77
Developer 1 Developer 2 Developer 3

36. Tagging and release
Once the code is merged into master production
$ git tag -a v1.0.1 # applies v1.0.1 tag to current commit
$ git tag # To list all tags
$ git tag -1 ‘v1.4.2*‘ # List all tags starting with 1.4.2
$ git tag -a v1.0.1 -m ‘my version 1.0.1’
$ git show v1.4
tag v1.4
Tagger: Scott Chacon <schacon@gee-mail.com>
Date: Mon Feb 9 14:45:11 2009 -0800
my version 1.4
commit 15027957951b64cf874c3557a0f3547bd83b3ff6
Merge: 4a447f7... a6b4c97...
Author: Scott Chacon <schacon@gee-mail.com>
Date: Sun Feb 8 19:02:46 2009 -0800
Merge branch 'experiment'

37. Tagging
Tagging later
$ git log --pretty=oneline
15027957951b64cf874c3557a0f3547bd83b3ff6 Merge branch 'experiment'
a6b4c97498bd301d84096da251c98a07c7723e65 beginning write support
0d52aaab4479697da7686c15f77a3d64d9165190 one more thing
6d52a271eda8725415634dd79daabbc4d9b6008e Merge branch 'experiment'
0b7434d86859cc7b8c3d5e1dddfed66ff742fcbc added a commit function
4682c3261057305bdd616e23b64b0857d832627b added a todo file
166ae0c4d3f420721acbb115cc33848dfcc2121a started write support
9fceb02d0ae598e95dc970b74767f19372d61af8 updated rakefile
964f16d36dfccde844893cac5b347e7b3d44abbc commit the todo
8a5cbc430f1a9c3d00faaeffd07798508422908a updated readme
$ git tag -a v1.2 9fceb02

38. Tagging

39. Everyday commands
Working on a new feature
$ git pull origin develop
$ git checkout -b adposting
.....did development work.....
$ git commit -am ‘Created new ad posting form’
$ git push origin adposting
......tested feature on development server.....
$ git checkout develop
$ git merge --no-ff adposting
$ git push origin develop:release-v1.1.2 (push to test server as release-v1.1.2
.........fix testing bugs on release v1.1.2.......
$ git fetch origin release-v1.1.2 ( on production only done by sysadmin )
$ git checkout master
$ git merge --no-ff release-v.1.1.2
$ git tag -am v1.1.2 ‘released version v1.1.2’

40. Everyday commands
Working on a hotfix
$ git pull origin master
$ git checkout -b hotfixv1.1.1 master
.....fixed bug on test server.....
$ git commit -am ‘fixed e-mail address on contact page’
....... Tested by deepak ........
$ git fetch origin hotfixv1.1.1 ( on production only done by sysadmin )
...... Check if already on master....if not $ git checkout master
$ git merge --no-ff hotfixv1.1.1
$ git tag -am v1.1.1 ‘released version v1.1.1’
$ git pull origin master ( on test and development servers)

41. Version numbering
v0.0.0
Major release Hot fixes
Minor releases

42. References
• Progit.org -- a complete book on git
• Gitref.org -- A very simple reference of all commands