Chapter 1 :- Introduction To Linux

Before learning about Linux we need to understand actually from where does it come from or what is the need for Linux so that it was developed and for that we have to go back in time from where it all started i.e 1969 when there is a time of Unix Operating System.

Unix is a multi-user, multi-tasking operating system. To understand this line we should know the meaning of Operating System.

Operating system (OS) is an interface between a computer hardware and user. An Operating System is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as printer, mouse, keyboard etc.

Operating System is a software that enables applications to interact with computer hardware like RAM, Processor, Hard drives etc.

Unix is a multi-user and multi-tasking operating system that means we can have many users logged into a system simultaneously and each users running many programs.

It is kernel's job to keep each process and user separate and regulate access to system hardware, including CPU, memory, disk and other Input Output Devices.

Unix first version was created in Bell Labs in 1969, Some of the Bell Labs programmers who had worked on this project are Ken Thompson, Dennis Ritchie, Rudd Canaday, and Doug Mcllroy.

These programmers worked together and implemented the first version of Unix File System on a PDP-7 along with few utilities. It was given the name UNIX by Brian Kernighan.

PDP 7 was the minicomputer produced by digital equipment corporation as part of the PDP series. Introduced in 1963, It was the First, to use their Filp-Chip technology

In June 1971, Richard Matthew Stallman joined MIT Artificial Intelligence Laboratory as a programmer where he gained popularity with the hacker community and came to be known by his now popular name RMS.

At that time, all the programmers used to share their code freely among each other cutting across various institution. In 1980, with the advent of portable software i.e. software that can be compiled to run on different computers, a business model emerged So companies developing the code refused to share the code with their clients and began restricting copying and redistribution of their software by copyrighting it.companies developing the code refused to share the code with their clients and began restricting copying and redistribution of their software by copyrighting it.

In response to this trend, Stallman, who believed in the principle that software has to be free always, founded the Free Software Foundation and in 1985, published the GNU Manifesto. This manifesto outlined his motivation for creating a free OS called GNU, which would be compatible with Unix. He along with a group of like minded programmers started work in developing the tools needed to make a complete OS.

In the same year (1985), a professor by name andy Tanenbaum wrote a Unix like Operating system from scratch for the Intel i386 platform. He named it Minix. In September 1989, Stallman released the first program independent GNU General Public License now popularly known as GPL or copyleft. Now the only thing that GNU lacked was a completely free OS kernel.

In 1990, A Finnish student by name Linus Torvalds studying in the University of Helsinki came into contact with Andy Tanenbaum’s OS, Minix. Linus wanted to upgrade Minix by putting in more features and improvements.

But he was prohibited by Tanenbaum to do so. Then Linus decided to write his own kernel and released it under GPL. This kernel is now popularly known as Linux.

Linux is a free Unix-type operating system originally created by Linus Torvalds with the assistance of developers around the world. It originated in 1991 as a personal project of Linus Torvalds, a Finnish graduate student.

The kernel version 1.0 was released in 1994 and today the most recent version is 6.0.10 (released on 26-nov-2022) Developed under the GNU General Public License, The source code of Linux is Open sourced.

Open Source Software are the software which the software in which source code are available to everyone.

The freedom to run the program for any purpose

The freedom to study and modify the source code

The freedom to redistribute the program

The freedom to create derivative programs

Due to these freedoms of open source software many companies created their own version of linux called Linux Distributions/Distros.

RedHat

Fedora

SuSE/Novell

Debian

And there are lots more.