Github how-to-use documentation for Beginners

Setting up a Windows Environment

• Goto https://git-scm.com/ and install git for windows
• Use special command line interface "Git Bash" which is easy to work with Git
• First we need to configure git on our local machine
  • git config --global user.name "TMK Computers"
  • git config --global user.email "computers.tmk@gmail.com"
  • git config core.editor "notepad++ -multiInst -nosession"
  • git config --edit --global

Creating git repository on local machine

• To create a new repository on local machine run below commands
  • git init DemoApp
  • cd DemoApp
  • ls -la
• You can check the status of repository with command
  • git status
• Create a new file README.md
  • notepad++ README.md
• Add some content in README.md. I have added "# Hello World". Save the file.
• Then check status again which shows status that we have an untracked file
  • git status
• Track the changes in README.md file with command
  • git add README.md
• If we have multiple new and edited files then we can track them all with a single command
  • git add .
• Then check status again which shows status that we have a staged file
  • git status
• Now we can commit the file with readable message
  • git commit -m "Intitial Commit"

Creating git repository on GitHub.com

• We can create a new repository on github.com with clicking on new New Repository button

• Choose a unique name within your account for new repository and add description also

• you have 3 options for working with newly created repository

  1. create a new repository on the command line

  - echo "# sample-repo" >> README.md
  - git init
  - git add README.md
  - git commit -m "first commit"
  - git remote add origin https://github.com/tmk-computers/sample-repo.git
  - git push -u origin master
  

  2. push an existing repository from the command line

  - git remote add origin https://github.com/tmk-computers/sample-repo.git
  - git push -u origin master
  

  3. import code from another repository

• We can check if local repository is connected with any remote repository

  • git remote -v

Using SSH to Connect with GitHub

• Command to generate ssh keys
  • ssh-keygen -t rsa -b 4096
• Goto the directory where key files are generated. Copy contents of file id_rsa.pub which public key file.
• Goto the github.com account, Select Settings -> SSH and GPG keys -> New SSH key page
• Add title, paste copied public key and click on Add SSH key button.
• Next you can test the SSH connection with command
  • ssh -T git@github.com

Fetching and Pulling from remote repository

• With below command you can get the changes to local git database. But these changes are not affected to the project directory of local repository
  • git fetch
• To affect all the fetched changes you can run command
  • git merge
• fetch and merge all the changes can also be done with single command
  • git pull
• If there is only change present in remote repository then git pull does fast forword merge.
• But if changes are done at both local and remote repositories then based on conflict present or not git pull takes separate actions.
• If there is no conflict then git pull creates automatic merge and then performs a new commit for merge usually called as “merge commit”
• If there is conflict then user has to do manual merge with mergetool
  • git mergetool --tool=emerge

Archiving Repositories

• You can mark non-active repositories as read-only with github feature Archiving Repository
• It adds a warning message at top as "This repository has been archived by the owner. It is now read-only."
• You cannot open an issue or pull requests - because of the repository is read-only.

Branching, Merging, and Pull Requests

• list all the branches present with command which also highlights current branch we are working now

  • git branch

• create a new branch of name dev with command

  • git branch dev

• switch to the newly created branch using

  • git checkout dev

• create a new branch and switch to it can be done by using single command

  • git checkout -b "new-branch"

• make some changes to new branch and commit those changes

  • git commit -m "Some changes are made in new branch"

• with below command newly created branch is pushed to remote repository where new branch is created to track our local branch

  • git push -u origin new-branch

• locally you can merge new-branch to master with command

  • git merge new-branch

• If there is conflict then user has to do manual merge with mergetool

  • git mergetool --tool=emerge

• Newly created branch can be merged with creating a pull request in github.

• The changes from pull request can be merged into master branch if any collaborator who has privilege approved it.

Working with Tags

• logs can be displayed with command
  • git log
• list of tags can be displayed with command
  • git tag
• new tag can be added to a branch with below command which adds a new tag with name "stable" to master branch
  • git tag stable master
• now we can list tags created with below command
  • git tag
• Now logs can be shown pretty readable with command
  • git log --online --graph --decorate -all
• Annotated tags can be added with command to point specific commit id
  • git tag -a v0.1 -m "0.1 release" a6b446e
  • git tag -a v0.2 -m "0.2 release" c3039bf
• Tags can be pushed from local to remote repository with command
  • git push --tags
• Delete tag locally
  • git tag -d "stable"
  • git tag -d "v0.2"
• If we try to push the deletion of tag to remote, tag will be removed from remote repository too.
  • git push origin :v0.2

Creating a New Release on GitHub

• Main difference between tag & release is release can also have release notes and other attachments such as binary files or compressed files
• You can create a release on github at code -> releases