LINUX OPERATING SYSTEMS

What is Linux

• Just like Windows XP, Windows 7, Windows 8, and Mac OS X, Linux is an operating system.

• An operating system is software that manages all of the hardware resources associated with your desktop or laptop.

Technical terms related to Linux

The Bootloader: The software that manages the boot process of your computer. For most users, this will simply be a splash screen that pops up and eventually goes away to boot into the operating system.

The kernel: This is the one piece of the whole that is actually called “Linux”. The kernel is the core of the system and manages the CPU, memory, and peripheral devices. The kernel is the “lowest” level of the OS.

Daemons: These are background services (printing, sound, scheduling, etc.) that either start up during boot, or after you log into the desktop.

The Shell is a user program or it's environment provided for user interaction. Shell is an command language interpreter that executes commands read from the standard input device (keyboard) or from a file. Shell is not part of system kernel, but uses the system kernel to execute programs, create files etc.

Desktop Environment: This is the piece of the puzzle that the users actually interact with. There are many desktop environments to choose from (Unity, GNOME, Cinnamon, Enlightenment, KDE, XFCE, etc)

Applications • Just like Windows and Mac, Linux offers

thousands upon thousands of high-quality software titles that can be easily found and installed

• Include App Store-like tools that centralize and simplify application installation. For example: Ubuntu Linux has the Ubuntu Software Center which allows you to quickly search among the thousands of apps and install them from one centralized location.

The ‘BIRTH’ of Linux Before Linux

In 1980’s main operating systems present were• Unix• Apple Mac• MS-DOS

1. DOS dominated the PC industry in 19802. Mac was considered technologically advanced than DOS but was

expensive3. Unix was even better but was much more expensive

1. People were looking for a UNIX based system, which is cheaper and can run on PC

2. DOS, MAC and UNIX were proprietary, i.e., the source code of their kernel is protected

3. No modification is possible without paying high license fees

The ‘BIRTH’ of Linux• FOUNDATION OF GNU

GNU (acronym for GNU’s not unix) was founded in 1984 by RICHARD STALLMANHe was against copying or modification in order to make better and efficient computer programs

• Aim at developing a complete Unix-like operating system which is free for copying and modification

• Stallman built the first free GNU C Compiler in 1991. But still, an OS was yet to be developed

The ‘BIRTH’ of Linux• Beginning of Linux

In Sept 1991, Linus Torvalds, a second year student of Computer Science at the University of Helsinki, developed the preliminary kernel of Linux, known as Linux version 0.0.1

Operating system MINIX was developed by professor Andrew Tanenbaun, a simplified version of Unix that runs on a PCIt was for education purpose only.

Soon more than a hundred people joined the Linux camp. Then thousands. Then hundreds of thousandsIt was licensed under GNU General Public License, thus ensuring that the source codes will be free for all to copy, study and to change.

Linux today• Today Linux is available for Desktops, laptops, tablets,

smartphones as well as independent machine systems

Not only character user interface but graphical user interface is available

Commercial vendors moved in Linux itself to provide freely distributed code. They make their money by compiling up various software and gathering them in a distributable format

– Red Hat, Slack ware, Canonical etc.

Free Linux

Free software, as defined by the FSF (Free Software Foundation), is a "matter of liberty, not price." To qualify as free software by FSF standards, you must be able to:

– Run the program for any purpose you want to, rather than be restricted in what you can use it for.

– View the program's source code. – Study the program's source code and modify it if you need to. – Share the program with others. – Improve the program and release those improvements so that

others can use them.

Linux is not a complete OS• Strictly speaking Linux is NOT the complete OS, but only

the kernel. The rest of the OS (called user-land) is mostly GNU-based. The correct naming of the OS is thus GNU/Linux.

• Without a kernel, an operating system doesn't exist. Without programs, a kernel is useless. In 1991, ideal conditions existed that would create Linux. In essence, Linus Torvalds had a kernel but no programs of his own, Richard Stallman and GNU had programs but no working kernel.

Linux distributions• A Linux distribution (often abbreviated as distro) is an

operating system made from a software collection, which is based upon the Linux kernel and, often, a package management system.

MAJOR LINUX DISTRIBUTIONS

To mention but only a few…

Linux on Smartphones• There are other smartphone operating systems in

development — and they’re all Linux-based.• Google’s Android operating system is also based on

Linux, although it’s very different from typical Linux distributions.

Ubuntu PhoneFirefox OSAmazon Fire OS

CREATING BOOTABLE PEN DRIVE ON WINDOWS

• We can install Linux on our computer using a bootable pen drive.

• Bootable USB can also be used to run Linux on a computer in LIVE MODE

Prerequisites• A Linux ISO file (Can be downloaded from websites of

respective distro)• Unetbootin : A software used to create bootable pen drive

(Universal USB installer or YUMI can also be used)• A pen drive 4gb or more.

• Select distro of Linux to be installed

• Select the version of distribution to be installed

• Browse the location of disk image

• Select Address of USB drive

• Click on ok

• Unetbootin completes the installing process. Select reboot

• How Ubuntu looks like on when we use bootable USB

The Linux desktop (Ubuntu with unity interface)

Looking Linux closely

UBUNTU Case studyIntroductionPhilosophyFeatures

Introduction• Ubuntu is a Debian-based Linux operating

system and distribution for personal computers, smartphones and network servers.

• It uses Unity as its default user interface.• Development of Ubuntu is led by UK-based Canonical

Ltd, a company owned by South African entrepreneur Mark Shuttleworth. Canonical generates revenue through the sale of technical support and other services related to Ubuntu.

Philosophy

• The Ubuntu project is publicly committed to the principles of open-source software development; people are encouraged to use free software, study how it works, improve upon it, and distribute it.

• It is based on free software and named after the Southern African philosophy of Ubuntu (literally, 'human-ness'), which Canonical Ltd suggests can be loosely translated as "humanity to others" or "I am what I am because of who we all are".

FeaturesUbuntu has a large set of popular app supportIt is the most widely used Linux Based OS

Features

• UPDATE CYCLE

• Ubuntu releases updated version in every nine month• And the versions are named as 13.04, 13.10, 14.04, 14.10 and so on…• Every fourth release is a long term support version• LTS version gets support and updates for 5 years• Current LTS version is 16.04

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