Git Basics

What is git ?

Git is version-control software that helps the software developers to collaborate with each other. Version control system helps to maintain history of changes that are made into the software.

Required terminology

• Repository:

  
  • It is container or we can say big box where contains all the files and folder and it is used by the git to keep track.
  • The repository stores number of projects and each project is shared among the team.Thus the access privilege is given to each authorized team member.

• Commit:

  
  • Commit is nothing but the saving your work.when you enter the commit command to repository then it take the pictures/snapshots of the files which are present at the time.
  • Result of the commit command only affects on local repository.
  • The function of version control is managed by the commit,where it stores the previous all version of the software

• Push & Pull:

  
  • Push is to make actual changes into remote repository by syncing from local repository.
  • Pull command is used to download and integrate remote changes.

• Branch:

  
  • Assume the git repository as a tree,so that the main software is called as master branch and all remain branches of that tree is called as branches.
  • Branches are separate instance of the code that is different from master branch/main codebase.
  • It helps to dividing the work into number of branches by giving seprate copy of codebase.Once all work is done and error free it will merge it back to master branch

• Merge:

  
  • It is kind of integration related to two branches where it helps to merge the branch with the master branch when branch is free of bugs.

• Clone:

  • Cloning is taking copy of entire online repository into the local machine.

• Fork:

  
  • Fork is similar to Clone except it takes entirely new repo of that code under your own name.
  • A forked repository differs from a clone in that a connection exists between your fork and the original repository itself.
  • In this way, your fork acts as a bridge between the original repository and your personal copy where you can contribute back to the original project using Pull Requests.

Git Internals

States related to file:

• 1. Modified:
  • file is changed but not committed to local repository.
  • this is genral modification of file content through notepad and any file editor.
• 2. Staged:
  • Before commit, You have to fire the git add command and tranfer file state from modified to staged.
  • Once command is fired, Check status by using git status command.
  • Marking the modified files in current version to go into next picture/snapshot is staging.
• 3. Commited:
  • data is safely stored and changed in local repo in form of pictures/snapshots.
  • To commit the file you have to fire the git commit command.

There are 3/4 different tress are maintained at one time of instance for your software code/repository.

Workspace, Staging, Local Repository, Remoter Repository

Git commands:

Getting & Creating Projects

Command	Description
git init	Initialize a local Git repository
git clone ssh://git@github.com/[username]/[repository-name].git	Create a local copy of a remote repository

Basic Snapshotting

Command	Description
git status	Check status
git add [file-name.txt]	Add a file to the staging area
git add -A	Add all new and changed files to the staging area
git commit -m "[commit message]"	Commit changes
git rm -r [file-name.txt]	Remove a file (or folder)

Branching & Merging

Command	Description
git branch	List branches (the asterisk denotes the current branch)
git branch -a	List all branches (local and remote)
git branch [branch name]	Create a new branch
git branch -d [branch name]	Delete a branch
git push origin --delete [branch name]	Delete a remote branch
git checkout -b [branch name]	Create a new branch and switch to it
git checkout -b [branch name] origin/[branch name]	Clone a remote branch and switch to it
git branch -m [old branch name] [new branch name]	Rename a local branch
git checkout [branch name]	Switch to a branch
git checkout -	Switch to the branch last checked out
git checkout -- [file-name.txt]	Discard changes to a file
git merge [branch name]	Merge a branch into the active branch
git merge [source branch] [target branch]	Merge a branch into a target branch
git stash	Stash changes in a dirty working directory
git stash clear	Remove all stashed entries

Sharing & Updating Projects

Command	Description
git push origin [branch name]	Push a branch to your remote repository
git push -u origin [branch name]	Push changes to remote repository (and remember the branch)
git push	Push changes to remote repository (remembered branch)
git push origin --delete [branch name]	Delete a remote branch
git pull	Update local repository to the newest commit
git pull origin [branch name]	Pull changes from remote repository
git remote add origin ssh://git@github.com/[username]/[repository-name].git	Add a remote repository
git remote set-url origin ssh://git@github.com/[username]/[repository-name].git	Set a repository's origin branch to SSH

Inspection & Comparison

Command	Description
git log	View changes
git log --summary	View changes (detailed)
git log --oneline	View changes (briefly)
git diff [source branch] [target branch]	Preview changes before merging

Git Workflow

For Quick Reference >>> Git Cheat Sheet