Git

Git , is a distributed revision control and source code management (SCM) system with an emphasis on speed. Initially designed and developed by Linus Torvalds for Linux kernel development, Git has since been adopted by many other projects. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server.

Stages

This is the main thing to remember about Git if you want the rest of your learning process to go smoothly. Git has three main states that your files can reside in:

• Committed,
  Committed means that the data is safely stored in your local database.
• Modified,
  Modified means that you have changed the file but have not committed it to your database yet.
• Staged,
  Staged means that you have marked a modified file in its current version to go into your next commit snapshot.

This leads us to the three main sections of a Git project: the Git directory, the working directory, and the staging area.

• Git directory
  The Git directory is where Git stores the metadata and object database for your project. This is the most important part of Git, and it is what is copied when you clone

a repository from another computer.

• Working directory
  The working directory is a single checkout of one version of the project. These files are pulled out of the compressed database in the Git directory and placed on disk for

you to use or modify.

• Staging area
  The staging area is a simple file, generally contained in your Git directory, that stores information about what will go into your next commit. It’s sometimes referred to as the index, but it’s becoming standard to refer to it as the staging area.

The basic Git workflow goes something like this:

1. Modify files in your working directory.
2. Stage the files, adding snapshots of them to your staging area.
3. Commit, which takes the files as they are in the staging area and stores that snapshot permanently to your Git directory.

Setup

To setup git

Username

First you need to tell git your name, so that it can properly label the commits you make.

 # Sets the default name for git to use when you commit.
 $ git config --global user.name "harm"

Email

Git saves your email address into the commits you make. We use the email address to associate your commits with your GitHub account.

 # Sets the default email account for git when you commit
 $ git config --global user.email "h.frielink@<you-server-name>"

Cheat Sheet

Always handy are Cheat Sheets .

Create & Clone		Add & Remove
Create new repo	git init	Add changes to INDEX	git add <filename>
Clone local repo	git clone /path	Add all changes to INDEX	git add *
Clone remote repo	git clone username@host:/path/to/repo	Remove / Delete	git rm <filename>

Commit & Synchronize		Branches
Commit changes	git commit -m "Message"	Create new branch	git checkout -b <branch> i.e.: git checkout feature-x
Push changes to remote repo	git push origin master	Switch to master branch	git checkout master
Connect local repo to remote repo	git remote add origin <server>	Delete branch	git branch -d <branch>
Update local repo with remote changes	git pull	push branch to remote repo	git push origin <branch>

Merge		Tagging
Merge changes from another branch	git merge <branch>	Create tag	git tag <tag> <commit-ID>
View changes between 2 branches	git diff <src-branch> <trg-branch>	Get commit IDs	git log