In this tutorial, we will learn about Git, the most popular source code management and distributed version control system.
The main features of Git are different users or groups can maintain their repositories, instead of working from a central repository. In Git the changes are stored as “changeset ” or “patches”.
The best way to learn about a new tool or technology is to install it in your machine and start working on it.
Git installation on the Linux machine.
Here I am installing Git on CentOS7 platform.
Execute the below command to install Git.
# yum install git
And to check the installed git version run below command
[root@techiescorner ~]# git --version git version 1.8.3.1
Now we have installed git, to work with this we need to configure it.
System-level configuration
This configuration applies to every user in the system. This configuration detail is stored in the /etc/gitconfig file
User-level configuration
This applies to a single user. So the configuration details will be in user home directory ~/.gitconfig.
Before starting user configuration I have created a new user (techies) for my system, to perform execute below command.
[root@techiescorner ~]# useradd techies [root@techiescorner ~]# su - techies Last login: Fri Feb 15 09:50:30 EST 2019 on pts/0 [techies@techiescorner ~]$
Let’s start the user-level configuration.
[techies@techiescorner ~]$ git config --global user.name "Techies Corner"
[techies@techiescorner ~]$ git config --global user.email "admin@techiescorner"
[techies@techiescorner ~]$ git config --list
user.name=Techies Corner
user.email=admin@techiescorner
[techies@techiescorner ~]$
All these details are stored in the user home directory.
[techies@techiescorner ~]$ ls -la
total 20
drwx------. 2 techies techies 101 Feb 15 09:56 .
drwxr-xr-x. 4 root root 36 Feb 15 09:50 ..
-rw-------. 1 techies techies 63 Feb 15 09:52 .bash_history
-rw-r--r--. 1 techies techies 18 Apr 10 2018 .bash_logout
-rw-r--r--. 1 techies techies 193 Apr 10 2018 .bash_profile
-rw-r--r--. 1 techies techies 231 Apr 10 2018 .bashrc
-rw-rw-r--. 1 techies techies 59 Feb 15 09:56 .gitconfig
[techies@techiescorner ~]$ cat .gitconfig
[user]
name = Techies Corner
email = admin@techiescorner
[techies@techiescorner ~]$
These are the minimum configuration needs to work with git.
Code editor configuration
used to set default text editor for git
[techies@techiescorner ~]$ git config --global core.editor "vim"
Global color configuration
By enabling this the git output will be displayed in different colors. It helps to understand git output easily.
[techies@techiescorner ~]$ git config --global color.ui true
Yes, we have installed and configured git, the next step is to initialize Git. To do this I am creating a new directory named “git-project”. To init Git execute below command
[techies@techiescorner git-project]$ git init Initialized empty Git repository in /home/techies/git-project/.git/ [techies@techiescorner git-project]$
Now we set /home/techies/git-project/.git/ as our Homebase or this is the Git repository and track all the files that come and go. The ‘.git’ directory is used to store all tracking information.
To understand the working of Git we will create a file called file1.txt with the following content in the git-project directory.
“This is the first file”
Now execute git add . ( Don’t miss the dot) to add all the changes that we made inside the directory, that is our project.
[techies@techiescorner git-project]$ cat file.txt This is the first file [techies@techiescorner git-project]$ git add .
Then perform the commit to save it in the repository.
[techies@techiescorner git-project]$ git commit -m "First commit" [master (root-commit) 4564c31] First commit 1 file changed, 1 insertion(+) create mode 100644 file.txt [techies@techiescorner git-project]$
-m stand for the message. Add some meaning full comment to understand it later, for example, support ticket number or bug tracking number. Here you can see we made 1 file change and 1 insertion.
Git commit log
git log command will help us to see the log of “git commit” that we just performed.
[techies@techiescorner git-project]$ git log
commit 4564c3181227e997cdb85acfee7a9a28d6d0babf
Author: Techies Corner <admin@techiescorner>
Date: Fri Feb 15 12:05:43 2019 -0500
First commit
[techies@techiescorner git-project]$
From the logs
commit: This is the commit ID, it is a unique code
Author: Who performed the commit
Date: Date and time, when the commit performed.
On the next page, we will understand Git architecture.
