Step-by-Step guide to Git

Hello, I will leave the link of my own programming youtube channel before I start to explain the subject. I am waiting for my youtube channel, where we will solve the algorithm and coding interview questions, and I will also explain the programming lessons in the future.

Link : https://www.youtube.com/channel/UCPgDzbHbAlj_TbjSxwoL8xQ

Git Installation

Let’s get into using some Git. First things first — you have to install it. You can get it a number of ways; the two major ones are to install it from source or to install an existing package for your platform

Installing from Source

If you can, it’s generally useful to install Git from source, because you’ll get the most recent version. Each version of Git tends to include useful UI enhancements, so getting the latest version is often the best route if you feel comfortable compiling software from source. It is also the case that many Linux distributions contain very old packages; so unless you’re on a very up-to-date distro or are using backports, installing from source may be the best bet. To install Git, you need to have the following libraries that Git depends on: curl, zlib, openssl, expat, and libiconv. For example, if you’re on a system that has yum (such as Fedora) or apt-get (such as a Debian based system), you can use one of these commands to install all of the dependencies:

When you have all the necessary dependencies, you can go ahead and grab the latest snapshot from the Git web site:

http://git-scm.com/download Then, compile and install:

After this is done, you can also get Git via Git itself for updates:

Installing on Linux

If you want to install Git on Linux via a binary installer, you can generally do so through the basic packagemanagement tool that comes with your distribution. If you’re on Fedora, you can use yum:

Or if you’re on a Debian-based distribution like Ubuntu, try apt-get:

Installing on Mac

There are three easy ways to install Git on a Mac. The easiest is to use the graphical Git installer, which you can download from the SourceForge page.

git-osx-installer

You don’t have to add all the extras, but you’ll probably want to include +svn in case you ever have to use Git with Subversion repositories

Homebrew (http://brew.sh/) is another alternative to install Git. If you have Homebrew installed, install Git via

Installing on Windows

Installing Git on Windows is very easy. The msysGit project has one of the easier installation procedures. Simply download the installer exe file from the GitHub page, and run it:

Git for Windows

After it’s installed, you have both a command-line version (including an SSH client that will come in handy later) and the standard GUI.

Introduction

At the command line, first verify that you have Git installed:

On all operating systems:

On UNIX-like operating systems:

If nothing is returned, or the command is not recognized, you may have to install Git on your system by downloading and running the installer. After installing Git, configure your username and email address. Do this before making a commit.

Once Git is installed, navigate to the directory you want to place under version control and create an empty Git repository:

This creates a hidden folder, .git, which contains the plumbing needed for Git to work. Next, check what files Git will add to your new repository; this step is worth special care:

Review the resulting list of files; you can tell Git which of the files to place into version control (avoid adding files with confidential information such as passwords, or files that just clutter the repo):

If all files in the list should be shared with everyone who has access to the repository, a single command will add everything in your current directory and its subdirectories:

This will “stage” all files to be added to version control, preparing them to be committed in your first commit. For files that you want never under version control, create and populate a file named .gitignore before running the add command. Commit all the files that have been added, along with a commit message:

This creates a new commit with the given message. A commit is like a save or snapshot of your entire project. You can now push, or upload, it to a remote repository, and later you can jump back to it if necessary. If you omit the -m parameter, your default editor will open and you can edit and save the commit message there. Adding a remote To add a new remote, use the git remote add command on the terminal, in the directory your repository is stored at.

The git remote add command takes two arguments:

1. A remote name, for example, origin
2. A remote URL, for example, https://<your-git-service-adress>/user/repo.git

NOTE: Before adding the remote you have to create the required repository in your git service, You’ll be able to push/pull commits after adding your remote.

Clone a repository

The git clone command is used to copy an existing Git repository from a server to the local machine.

For example, to clone a GitHub project:

To clone a BitBucket project:

This creates a directory called projectname on the local machine, containing all the files in the remote Git repository. This includes source files for the project, as well as a .git sub-directory which contains the entire history and configuration for the project.

To specify a different name of the directory, e.g. MyFolder:

Or to clone in the current directory:

Note:

1. When cloning to a specified directory, the directory must be empty or non-existent.
2. You can also use the ssh version of the command:

The https version and the ssh version are equivalent. However, some hosting services such as GitHub recommend that you use https rather than ssh.

Sharing code

To share your code you create a repository on a remote server to which you will copy your local repository. To minimize the use of space on the remote server you create a bare repository: one which has only the .git objects and doesn’t create a working copy in the filesystem. As a bonus you set this remote as an upstream server to easily share updates with other programmers.

On the remote server:

On the local machine:

(Note that ssh: is just one possible way of accessing the remote repository.)

Now copy your local repository to the remote:

Adding — set-upstream (or -u) created an upstream (tracking) reference which is used by argument-less Git commands, e.g. git pull.

Setting your user name and email

You need to set who you are *before* creating any commit. That will allow commits to have the right author name and email associated to them.

It has nothing to do with authentication when pushing to a remote repository (e.g. when pushing to a remote repository using your GitHub, BitBucket, or GitLab account).

To declare that identity for all repositories, use git config — global

To declare an identity for a single repository, use git config inside a repo. This will store the setting inside the individual repository, in the file $GIT_DIR/config. e.g. /path/to/your/repo/.git/config

Settings stored in a repository’s config file will take precedence over the global config when you use that repository. Tips: if you have different identities (one for open-source project, one at work, one for private repos, …), and you don’t want to forget to set the right one for each different repos you are working on:

Remove a global identity

If Version ≥ 2.8

That way, if you forget to set your user.name and user.email for a given repository and try to make a commit, you will see:

Setting up the upstream remote

If you have cloned a fork (e.g. an open source project on Github) you may not have push access to the upstream repository, so you need both your fork but be able to fetch the upstream repository.

First check the remote names:

If upstream is there already (it is on some Git versions) you need to set the URL (currently it’s empty):

If the upstream is not there, or if you also want to add a friend/colleague’s fork (currently they do not exist):

Set up SSH for Git

If you are using Windows open Git Bash. If you are using Mac or Linux open your Terminal. Before you generate an SSH key, you can check to see if you have any existing SSH keys.

List the contents of your ~/.ssh directory:

Check the directory listing to see if you already have a public SSH key. By default the filenames of the public keys are one of the following:

If you see an existing public and private key pair listed that you would like to use on your Bitbucket, GitHub (or similar) account you can copy the contents of the id_*.pub file. If not, you can create a new public and private key pair with the following command:

Press the Enter or Return key to accept the default location. Enter and re-enter a passphrase when prompted, or leave it empty.

Ensure your SSH key is added to the ssh-agent. Start the ssh-agent in the background if it’s not already running:

Add you SSH key to the ssh-agent. Notice that you’ll need te replace id_rsa in the command with the name of your private key file:

If you want to change the upstream of an existing repository from HTTPS to SSH you can run the following command:

In order to clone a new repository over SSH you can run the following command: