Introduction to Git and Github

This presentation introduces the basics of git to developers using the github platform.
After this presentation, users should be able to start using git effectively to manage and collaborate in projects

Transcript

1. Up and Running with Git
2. ABOUT ME @bernard_parah on Twitter parah@bitnob.com barjebernard@gmail.com BERNARD BETA PARAH bitnob.com SOFTWARE ENGR @ BITNOB TECHNOLOGIES
3. Outline What is version Control System Why do you need to use one? Popular Web Version Control Systems Git Commands Demo Project
4. The Problem
5. You made a major mistake in your project, by introducing breaking changes and you need to revert to a working version of your code…
6. BUGS EVERYWHERE You have made so many changes already, in so many files. You can’t even remember what exact changes even if you can remember all the files If you remember all, it will take you a lot of time to CTRL + Z all the mess
7. Now you realize even this can’t save you.
8. So what is Git? ➔ An open-source project developed by Linux Torvalds in 2005 ➔ Git is an open-source Distributed Version Control System ➔ A command line utility Let us breakdown this seemingly complex term …. Distributed Version Control System
9. Distributed The code is not kept on any single central server, it is kept on multiple computers. A loss on one computer can easily be recovered by getting the same code from another computer that is storing a copy of it. You get the full history of the project as well.
10. Version Control System For every change made to a project, a new version of the project is created, this helps keep track of the state of the project at any given point in time. This keeps a history of what happened throughout the life history of the project.
11. Why do we need git? ➔ Allow multiple developers work in parallel ➔ Allow developers to quickly revert to a working version of a project ➔ Different features might be built simultaneously, this introduces the concept of branching
12. Git Structure You can imagine git as a tree structure and all the commands you run are to navigate or manipulate that tree. Any new commit creates a new node(leave) on the tree structure
13. Git Structure If you understand how the Git repository is a tree of commits and see how operations like branching, merging, pushing, and pulling manipulate that tree, then understanding other Git commands should not be difficult.
14. Working with Git Repositories A Repository is a data structure where git stores information in. A git repository is made up of: • A set of commit objects. • A set of references to commit objects, called heads.
15. Git Structure You can imagine git as a tree structure and all the commands you run are to navigate or manipulate that tree. Any new commit creates a new node(leave) on the tree structure
16. Commit Objects A commit object contains is made up of 3 things: • A set of files, reflecting the state of a project at a given point in time. • A commit message, describing what the commit was about • An SHA1 name, a 40-character string that uniquely identifies the commit object. The name is composed of a hash of relevant aspects of the commit, so identical commits will always have the same name. commit 26a02bd03ca716949f9d819a89e35c4a9b603aff
17. Next Steps
18. Installing Git ➔ Go to https://git-scm.com and install the version of your choice ➔ Configure your git setup globally to control all your git operations on the computer
19. Git Config Set your identity, you will only need to do this once $ git config --global user.name "John Doe" $ git config --global user.email johndoe@example.com You can check your settings by running: $ git config --list
20. Create a local git repository $ mkdir git_play $ cd git play $ git init
21. Create a remote git repository • Create an account on github.com • Create a repository
22. Create a remote git repository • $ cd git_play • $ git clone <repository url>
23. Add remote url Create a file Index.txt 1. Introduce a change to the file 2. Introduce the change by adding it to the staging area : $ git add index.txt 3. Commit the change : $ git commit -m “made a file change” 4. Push the change : $ git pull origin master
24. Git Init $ git init This creates a new git repository or converts an unversioned project into a git project. This can also be used to reinitialize a git repository back to a clean state
25. Git add <filename1> <filename2> $ git add index.html style.css Use this command to add specific files that have been changed to the staging area
26. Git add . $ git add . Use this command to add all files that have been made to the staging area
27. Git Remote $ git remote add origin <repository url> Use this to connect the local and remote repositories
28. Pull $ git pull origin <branch name> Use this command to pull remote changes from the named branch.
29. Push $ git push origin <branch name> Use this command to push local changes to the named remote branch.
30. Branch $ git branch <branch-name> Use this command to create a new branch
31. Switch Branch $ git checkout <branch-name> Use this command to switch to the named branch Ps: it is best practice to commit the code on the current branch before switching
32. Check Current Branch $ git branch This command lists all the branches and indicates the current branch as well
33. Create branch and checkout $ git checkout -b <branch-name> Use this command to create a branch and switch to the branch
34. Merge $ git merge <branch-name> Use this command to merge changes from the named branch into a single branch. This command is usually used in conjunction with GIT CHECKOUT.
35. Log $ git log Use this command to view all the commits logs
36. Diff $ git diff Displays the changes that have been made
37. Status $ git status Displays the files that have been added, untracked and modified
38. Fetch $ git fetch Get changes from a remote repository without the changes affecting your current work. This is usually a harmless form of git pull.
39. Stash $ git stash This command creates a record of the current work while switching you back to the last clean working version
40. My personal workflow usually looks like: 1. Do some programming. 2. git status to see what files I changed. 3. git diff [file] to see exactly what I modified. 4. git commit -a -m [message] to commit.
41. QUESTIONS?
42. Thank you very much