Version control with Git — 1

Git is a free and open source version control system. Learning how to use it is a lesson for every developer. There's a lot of articles and clips teaching you how to do it, I'm not going to completely introduce Git. Just providing a brife note I took when I learned to do it. So, if you're new to Git, too, follow the steps bellow and get confortable making any changes.
Open your Terminal on Mac
You can use Mac spotlight to find it.
Create directory and file
First, I'm going to the desktop. By typing the code below:
$ cd desktopAnd then, I make a new directory named git-fun:
$ mkdir git-funNow you can see there’s a new folder shows on your desktop, we can do
$ cd git-fun
$ git init to get into git-fun and initialize the directory. Always need to initialize it when you create it, and it can be used with git.
Now I create a new file named README.md in git-fun.
$ touch README.mdIf you type

$ lsit will show all the files in this directory, and now there is only README.md, which you just created.
$ vim README.mdWe can edit README.md, and let’s add a line in the file like this:

press
ican insert content, when you finish edit it, pressESCtwo times and pressShift+:and typeXand pressEnterbutton can save and leave the edit mode.
Add and Commit the file
By doing
$ git status it will show the message like this:

It means that git is not tracking this file, it will not go in your git repository unless you start tracking file. Now we need to save this file, the first thing we need to do is add this file by:
$ git add README.mdand then $ git status check what is change,

It become green, and says there is a new file README.md now. So now we can commit it. Any time you commit a file it’s like a time stamp, it save this version in your history. Anytime when you go back to see, it will like the way it did when you did that commit.
$ git commit -m "first commit"Check $ git status , and you will see there is noting to commit, working directory is clean. We have now committed that change in history.
Command + K can clear the screen of terminal.
Edit README.md and Add A New File
Add a new line in the file. (Just trying to make some change, and we can use version control to recover the previous version.
$ vim README.md//Edit the file, here I add a new line

$ git status //it will show modified: README.md$ touch code.js //just for show the difference$ git add -A //Add all the files at the same time$ git commit -m "modified README.md and added code.js file"$ls //README.md code.js
Git log and branch
Now we had edited our README.md file. BUT! If now you regret the change , you want to bring back the previous version which only one line in the file.
First,
$ git logIt will show all the commit you have done. And now you will know why the message is so important, it help you to know which one you are finding.
$ git checkout 951e1fa// 951e1fa is the first seven digits of that commit.

Now if you do $ ls , there is only one file README.md
Version control has now checked out the the previous version. Now we can put this version in another branch to save it.
$ git branch // Show all the braches I have now $ git checkout -b readme-one-line //name this new branch as readme-one-line$ ls // README.md (one line version)$ git checkout master //Switch to master branch$ ls // README.md (two lines version) code.js
And now I successfully have multiple versions of our code.
Notes: The more often you commit, the more safe you code can be. But don’t commit bug, and don’t commit trash. Always do
$ git status, to make sure what you did.
