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 .

Information
Status Repo	git status

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

Github flow

At GitHub, we use our products every day and have developed a workflow to collaborate on projects. To make it work for teams regardless of their size or technical expertise, we made sure each step in our workflow can be completed within a web-based interface.

1. Create a branch from the repository, Delete a branch from the repository.
2. Create, edit, rename, move, or [[#Delete file|delete] files.
3. Send a pull request from your branch with your proposed changes to kick off a discussion.
4. Make changes on your branch as needed. Your pull request will update automatically.
5. Merge the pull request once the branch is ready to be merged.
6. Tidy up your branches using the delete button in the pull request or on the branches page.

Create a branch

1. On GitHub, navigate to the main page of the repository.
2. Click the branch selector menu.
3. Type a unique name for your new branch.
4. Press Enter.

Delete a branch

1. On GitHub, navigate to the main page of the repository.
2. Above the list of files, click NUMBER branches.
3. Scroll to the branch that you want to delete, then click the trash-bin.

Create, edit, rename, move, or delete

Create file	Edit file	Rename file	Move file	Delete file
On GitHub, navigate to the main page of the repository. In your repository, browse to the folder where you want to create a file. Above the file list, click Create new file. In the file name field, type the name and extension for the file. To create subdirectories, type the / directory separator. On the Edit new file tab, add content to the file. To review the new content, click Preview. At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request. Click Propose new file. More...	In your repository, browse to the file you want to edit. In the upper right corner of the file view, click the pencil-icon to open the file editor. On the Edit file tab , make any changes you need to the file. Above the new content, click Preview changes. At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request. Click Propose file change. More...	In your repository, browse to the file you want to rename. In the upper right corner of the file view, click the pencil-icon to open the file editor. In the filename field, change the name of the file to the new filename you want. You can also update the contents of your file at the same time. At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request. Click Propose file change. More...	In your repository, browse to the file you want to move. In the upper right corner of the file view, click the pencil-icon to open the file editor. In the filename field, change the name of the file using these guidelines: To move the file into a subfolder, type the name of the folder you want, followed by /. Your new folder name becomes a new item in the navigation breadcrumbs. To move the file into a directory above the file's current location, place your cursor at the beginning of the filename field, then either type ../ to jump up one full directory level, or type the backspace key to edit the parent folder's name. At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request. Click Propose file change. More...	Browse to the file in your repository that you want to delete. At the top of the file, click the 'Trash-bin'. At the bottom of the page, type a short, meaningful commit message that describes the change you made to the file. Below the commit message fields, decide whether to add your commit to the current branch or to a new branch. If your current branch is master, you should choose to create a new branch for your commit and then create a pull request. Click Propose file change.

Send a pull request

See https://help.github.com/articles/about-pull-requests

Make changes

Just do the necessary changes.

Merge

See https://help.github.com/articles/merging-a-pull-request

Tidy up

See https://help.github.com/articles/deleting-and-restoring-branches-in-a-pull-request

See also

• GitHub is the best place to share code with friends, co-workers, classmates, and complete strangers. Over eight million people use GitHub to build amazing things together.
• Cloudforge, Free Git repository Website for all your code.

Tutorials

• Tutorial, Introduction to git 1.5.1. or newer.
• Read-Write, Github for beginners.