Git Real - Level 1

Notes from Code School's Git Real Course - Level 1

Intro to Git

Git is a version control repository that lives locally on your machine. It helps manage files by tracking changes as well as taking snapshots of your work. These snapshots are recorded in a timeline for your reference, as well as for your use, if you wish to go back to previous versions of your work. Git does not take these snapshots automatically, you must manually "stage" and "commit" them. Staging is basically choosing which items to "take a picture of", and committing means "taking the picture".  Git can help you manage files remotely as well (more later).

- Git is mostly run through the command line tool.
- You must first install Git. Go to: http://git-scm.com/book/en/Getting-Started-Installing-Git


$ git help  Use this command to access Git's help topics and list of commands

$ git help <command>  Use this command to get help on a specific command, e.g.s (config, init, and diff are Git commands)
    $ git help config
    $ git help init
    $ git help diff



You will need to configure a global user name and email for your Git (one time set up)

$ git config --global user.name "<name>"  
$ git config --global user.email <email>

e.g.s
      $ git config --global user.name "Helen"
    $ git config --global user.email helen@example.com

    $ git config --global user.name "Adam"
    $ git config --global user.email adam@gmail.com

    $ git config --global user.name "Jules"
    $ git config --global user.email juliet@isababy.com

Note:
- "global option", I'm guessing this has a local or some other counterpart, but at this time I don't really know
- Quotes are required around the user.name, "Helen", but not for the user.email, helen@example.com. This kind of inconsistency drives me mad.

To add pretty color styling to your command line, add
$ git config --global color.ui true

How to Create a New Local Git Repository

To start using Git, you first must have a project started. Maybe its an empty folder at this point, or maybe its a new rails app. Doesn't matter, just know that your command line must be within the project folder you want to apply the Git version control.

e.g.
  Helen-Williamss-MacBook-Pro: ~hwilliams$ (this is my home folder)
  Helen-Williamss-MacBook-Pro: blog_app hwilliams$   (this is the folder for the project I want to use Git for)

Create a new local Git Repository
$ git init

What this does:
- Creates a local Git repository called ".git"
- ".git" is a local hidden file
- Git metadata is stored here
- You do not need to access this file, just know that it is there.
- If you open your project folder (using GUI graphical user interface), you will see the .git file, e.g. /hwilliams/blog_app/.git

About Git Workflow

- Create a file (it is untracked at this point)
    Note: Although this file is "untracked", Git knows its there (creepy? I think so). So it IS tracked, in a sense. But it is not under version control yet, so we'll call it "untracked".
- Add file to staging area (this is the file you want to take a snapshot of)
- Commit file (take a snapshot of file)

Another example of Git workflow:
- modify file (Say you make a change to a file you already committed)
- add file to staging area (Prepare it to get its picture taken)
- commit file (Take picture)

Git Workflow Commands (status, add, commit, and log)

$ git add <filename> 
- This adds your file to the staging area

$ git status
- Run this to view all files that are currently in the staging area

$ git commit -m "a message that describes your commit" 
- Commit all files currently in the staging area with a descriptive message so when you come back later, you know what the heck you did (also helpful for others to see what you did)

$ git log
- Run this to see the commits you've already made (and read those helpful descriptions so you know what's going on).

e.g.
$ git add README.txt
  (adds README.txt to staging area)

$ git status
  (Will output a dialog in pretty colors saying README.txt is currently staged)

$ git commit -m "Add README.txt"
  (Takes picture of README as it exists at that exact point in time, with a nice descriptive message of course.)

$ git log
  (Will output a dialog showing that README.txt was committed with the text "Add a README.txt")

-Note: Commit messages should be in the present tense, otherwise you will confuse your future self because time is like, relative.

e.g. 2
$ git add README.txt index.html
  (note: no quotes or commas when adding multiple files at once)

$ git add myprettystyles.css
  (oops, need this one too! adds myprettystyles.css to staging area)

$ git status
  (Outputs dialog showing README.txt, index.html, and myprettystyles.css are all in the staging area)

$ git commit -m "Modify README.txt, Create index.html and myprettystyles.css"

The Timeline

When you make a commit it adds the files to the HEAD. Use $ git log to view your commits.

Different Ways to Add Files to the Staging Area

$ git add <list of files>
      Add a list of files to the staging area (note: no quotes or commas separating file names)
      e.g.s
        $ git add index.html about.html contact.html
        $ git add styles.css index.html README.txt routes.rb
        $ git add application.rb posts.html.erb

$ git add --all 
    Add all files in the current directory to the staging area

$ git add *.txt
    Add all .txt files in the current directory to the staging area. Substitute any filetype for 'txt'.
    e.g.s
      $ git add *.txt       (adds all text files)
      $ git add *.css       (adds all css files)
      $ git add *.html.erb  (adds all erb files)

$ git add app/*.txt
    Add all .txt files in the app folder to the staging area. Substitute your folder name for 'app', and any filetype for 'txt'.
   e.g.s
               $ git add mydocs/*.txt
      $ git add app/*.html
      $ git add stylesheets/*.css

$ git add app/
   Adds all files in the app folder to the staging area. Substitute your folder name for 'app'
  e.g.s
      $ git add mydocs/
      $ git add app/
      $ git add stylesheets/

$ git add "*.txt"
  Add all .txt project files to the staging area, not just the ones in the current directory. Substitute any filetype for 'txt'.
e.g.s
      $ git add "*.txt"
      $ git add "*.css"
      $ git add "*.html"


About this blog: This blog is an attempt to summarize my learnings as I learn them. Expect inaccuracies, incompleteness and inconsistencies.