A dummy's guide to Version Control and a brief introduction to GIT and GIT commands.

1. Version Control
GIT Primer
AUG 2015
Saad Ulde

2. Version Control GIT
● The What
● The Why
● The How
● Popular Implementations
Conclusion
● Introduction
● Branching
● Installation
● Commands
● Gitlab
● Demo and Hands-on
● Conflicts!
● Conflict Resolution
● Caveats
● Useful commands
● Q&A
Outline

3. What is Version Control?
Provides
● Create
● Save
● Edit/Modify
● Save AGAIN – This is where Version Control
comes in!
Daily Tasks for a Developer
● When was the change made?
● Why was it made?
● What the changes were?
● Who did it?

4. History Tracking Version Control | History Tracking | Individual
Individual Tracking

5. History Tracking Version Control | History Tracking | Collaboration
Collaborative Tracking

6. Popular Implementations Version Control | Popular Implementations
Distributed Centralized
● Peer-to-peer approach
● Entire copy of the codebase is replicated
● Changes go in the local repository first, and if
need be, shared with others
● Platforms - GIT, Mercurial, Bazaar etc.
● Software's – Gitlab, GitHub, Bitbucket etc.
● Client-server approach
● Only the server has the entire copy
● Changes go directly to the central repository
● Collaborators see the change immediately
● Platforms – SVN, ClearCase etc.
● Software's – TortoiseSVN, SmartSVN etc.

7. GIT
Introduction Terminologies
● GIT is an implementation of distributed style
Version Control
● Minimal efforts for setting up
● Highly customizable
● Can be installed locally (on a single computer)
or on a server (on a network)
● Developers can use CLI, desktop applications
or web application to see the see their
repositories
● Working directory – Actual files that you are
working on
● Index – Staging area
● HEAD – points to the last commit you did
● Remote repository – The main or the central
copy of the repository
● Local repository – The local version of the
central repository

8. Branching GIT | Branching
● Branches are used to develop separate and isolated features
● Master branch – The default branch when you create a
repository
● You can create (split) branches from any branch
● You can merge it back to the parent branch once the
development is over

9. Installation GIT | Installation
● All major platforms supported
● https://git-scm.com/download
● Configuring the username and email
● Initializing a repository

10. Basic Commands GIT | Commands
● git init <project name> – initializes a new repository
● git status – Get a list of files modified on locally
● git add <file name> – Adds the file to the staging area
● git commit -m “<message>” – Commits all the files that were added to the staging area
● git diff <file name> – Lists the changes made to the file when compared to the HEAD version
● git checkout <file name> – Restores the file with the HEAD version
● git checkout [-b] <branch name> – Switches the branch, the –b parameter will create a new branch
● git stash – Backups up any local changes made
● git stash apply – Restores the most recent backed up files
● git pull – Pulls the latest changes from the repository
● git reset HEAD – Removes all the local changes made to the files that are already in the repository
● git reset [-–hard] HEAD <file name> – Will unstage all the file if it was staged else it will remove all the local changes
made to the file
● git push origin <branch name> - Pushes the changes in the local repository to the remote repository
● git rm <file name> - will remove the file from the working area and the stage the removed file

11. Gitlab GIT | Gitlab
● Introduction to Gitlab
● Walkthrough and different elements on the UI
● Issue tracking
● Wiki
● Merge requests
● Milestones
● Commits

12. Conflicts! GIT | Conflicts!
● Index.html is a existing file
● User 1 modifies the footer div in it and pushes the new changes
● User 2 is simultaneously modifying the footer section of the same file, once he is done with his changes he takes a pull
● User 2 does a stash apply, git prompt will throw an error since they both were working on the same section of the same file
Scenario

13. Conflict Resolution GIT | Conflict Resolution
● Open the file that has the conflict in it, the conflicting section should look similar to this -
● The lines between <<<< and ==== indicate the changes done in the remote branch, and the lines between ==== and >>>> indicate
your changes
● Once you decide which part you want to keep you can delete those 3 lines
● Follow this by either git reset HEAD <file name> or git add<file name> depending on whether you want to stage the
file or not
● Voila! Conflict resolved!

14. Caveats Conclusion | Caveats
● Peer-review
● Concise commit messages
● Link the bug number in the commit messages if it’s a bug fix
● Push stable and error free code
● If the commit is a partial feature, then make sure you are mentioning it in the commit message

15. Useful Commands Conclusion | Useful Commands
● Ever so often, it may happen that a commit needs to be reverted
● git revert <commit id> - Reverts the commit with the commit id mentioned, and prepare a commit with the reverted changes
● git cherry-pick <commit id> - Specifically pull the commit from other branch and add it to the current local branch and
stage the changes

16. Q&A

17. Thank You