Day 2: #90DaysOfDevOps

Operating System(OS) is required for a computer to perform basic tasks such as:

1. Managing the software and hardware
2. Establishing a user interface
3. Executing and providing services for applications software
4. Providing an interface between the user and the computer
5. Booting
6. Managing the input/output devices
7. Multitasking
8. Managing the software and hardware
9. Establishing a user interface
10. Executing and providing services for applications she memory
11. Managing the system files
12. Providing security
13. Carrying out important tasks such as program scheduling
14. Controlling peripheral devices such as disk drives and printers.
15. Loading programs onto the main memory until execution is completed.

and many more.

Without an OS, a computer is just an object. Every application would need to include its own UI, as well as the comprehensive code needed to handle all low-level functionality.

Linux is one of the most commonly used OS all over the globe.

History of Linux:

- It was developed by Linus Torvalds in 1991 when he was a student at the University of Helsinki, Finland, USA.
- On Sept 17, 1991, he published the initial code of Linux 0.01 and released it on the Minix Newsgroup.
- As soon as his code gained popularity, he was inspired to develop a new version, and on October 5, 1991, he officially released Linux v 0.02.
- It is open-source and comes from a UNIX family and today it is used by 91% of applications on the internet.

Linux Architecture:

User Application -> Shell -> Kernel -> Hardware

The Kernel is an operating system's central component. The software is in charge of executing programs and granting safe access to the hardware of the computer. The kernel also selects the start and end times of each program because there are many of them and not enough resources.

We can't interact with Kernel directly in order to make the communication we use Shell to interact with Kernel. Based on the command request Kernel executes the related command and makes the required allocation in Hardware.

Linux File System Hierarchy:

Everything in Linux is files, folders, or directories.
Linux uses a single-rooted, inverted tree-like structure.
Forward Slash(/) represents the Root directory which is a top-level directory.

Basic Commands:

mkdir: to create a directory.
cd: to change the directory.
clear: to clear the screen.
pwd: to show the present working directory.
ls: to list the content of the present working directory.
touch: to create a file.
cp: to copy and paste file or folder.
mv: to move the file or folder.
date: to show time & date.
uname: it shows the name of the kernel.
uname -r: it shows the version of the kernel.
whoami: to show the current user name.

That is all for today, we'll continue tomorrow. Happy Learning.