Git Intro

For full blog, click here

Version Control System (VCS)

A system that saves multiple versions of a file. This allows tracking of changes, reverting back to a previous version, tracking modifications along with their creators, and comparing changes.

• Local Version Control: One database on your hard disk that stores changes to files
• Centralized Version Control (CVCS): Better for collaboration, entails a single server storing all changes and versions, can be accessed by multiple clients. Team members can track changes and activity from other members.
• Distributed Version Control (DVCS): Allows clients to create mirrored repositories. Data backups can be easily used to replace any lost information. Solves the issue of the CVS being a single point of failure.

Git

• Git is a DVCS that stores data in a file system made up of snapshots. Git records and saves a snapshot of all changes to a project (commits)
• Git relies on local operations due to important information being found on the local disk, this allows work to be done offline or when not on a VPN
• Git tracks all changes and detects file corruption
• Git makes you jump through hoops in order to completely lose data, preventing accidents
• The states of Git: Committed (data stored in a local database), Modified (file has been changed, but not committed), Staged (Flagged changed version to be commited in next snapshot)

Let’s Get Started

Download Git:

1. Install as a package
2. Install via another installer
3. Download and compile the source code

• Max OS, Windows, and Linux all have different methods for download, click the blog link above to read about the specifics for your system

If you would like Graphical User Interface (GUI) tools, visit this link for options

Initial Customization

Configuration of Variables: Use Git tool git config Identity Setting: set your username and email address to be used for every Git commit

In the terminal type:

  git config --global user.name "Jane Smith"

  git config --global user.email "example@email.com"

Default Text Editor: Git uses your system’s default editor, to switch editors, type into your command line:

  '$ git config --global core.editor (name of editor)'

• Note Some editors require specific instructions

Check Your Setting: Use the ‘git config –list’ command

Setting Up a Git Repository

Importing To import an existing project or directory into Git, type into your terminal:

1. Switch to target project’s directory: $ cd test (cd = change directory)
2. Use the git init command: $ git init
3. Start tracking these files:
   • $ git add *.c
   • $ git add LICENSE
   • $ git commit -m “any message here”

Cloning Clone an existing repository from a particular server with clone command: $ git clone ‘the repository’s URL’

• This will create copies of all versions of all files for a project.

Workflow

Local Repository Structure:

1. Working Directory: The actual files reside here
2. Index: The area used for staging
3. Head: Points to the most recent commit

Saving Changes

• Tracked: files can be modified, unmodified, or staged
• Untracked: files not a part of the last snapshot, do not currently reside in the staging area

The Life cycle of File Status

unmodified ➡️ edit the file ➡️ modified ➡️ stage the file ➡️ staged ➡️ commit the file ➡️ unmodified

Tracking and Staging a New File

• Single File: use format ‘git add filename’
• All Files: use command ‘$ git add *’

Committing a File

After staging, commit the changes and write a commit message of what you did

• $ git commit -m “made change x,y,z”
• To commit all changes - $ git commit -a

Pushing Changes

• $ git push origin master

This command pushes changes from the local “master” branch to the remote repository named “origin”

Stashing Changes

• Use ‘git stash’ to store changes that you dont want to commit yet
• Use ‘git stash apply’ to retrieve hidden changes

Remote Repositories

Versions of a project found online or on a network - push and pull data from these repositories!

• Cloned repositories: “origin” is the name of the initial server that got cloned, and “master” is your local branch

Seeing Your Remotes

• Run ‘git remote’ command to view short names of remote handles
• Run ‘git remote -v’ to view all remote URLs and their short names

Return home