Introduction and Overview

Questions answered in this lecture:What is an operating system?History of Linux ?Comparison between Linux & Windows?

University of Education

Linux Operating Systems Muhammad Amer Irshad

Operating System

What is an Operating System?

OS:Everything in system that isn’t an application or hardware

OS:Software that converts hardware into a useful form for applications

Not easy to define precisely…

Users

Hardware

Operating System

ApplicationsCompilers databasesword processors

CPUmemoryI/O devices

First commercial systems

1950s Hardware• expensive, and slow• Input/Output: Punch cards and line printers

Goal of OS• Get the hardware working• Single operator/programmer/user runs and debugs

interactively

Current Systems

Conclusion: OS changes due to both hardware and users

Current trends• Multiprocessors• Networked systems• Virtual machines

OS code base is large• Millions of lines of code• 1000 person-years of work

Code is complex and poorly understood• System will always contain bugs• Behavior is hard to predict, tuning is done by guessing

A Brief History of

Linux Operating System

Bell Labs

C

Unix

Unix was created by Ken Thompson and Dennis

Richie on a "spare" DEC PDP-7

Why Unix? To play games faster on company

hardware. To experiment more with creating a multi-

user multi-tasking computer system. This didn't happen in Windows until XP.

Ken Thompso

n and Dennis Richie

Every job needs a tool

The C programming language was created to be a systems programing language. “C is a... systems implementation language. It was

designed ... to provide low-level access to memory, to provide language constructs that map efficiently to machine instructions, and to require minimal run-time support. C was therefore useful for many applications that had formerly been coded in assembly language.”

C has expanded to be used for general application use.

Called C because many features came from an early programming language called B.

Hello, World!

Early Unix History

Work began in 1970 on Unix. The name is a pun on Multics (Unics). The first application was a word process

(1971). C was developed in 1972. In 1973 Unix was rewritten in C.

Writing system code in a language was unheard of.

Allowed for portability.

Unix growth

For a modest fee Bell Labs would send you the source code.

Became popular for universities and students for to us as example code.

Minix was developed to teach student systems level programming.

GNU Manifesto

Richard Stallman started GNU (circa 1985)

End goal was a free Unix-like system.

Developed clones of Unix utilities that were often better than the originals.

The kernel was not developed at this time.

Linus Torvolds

Wrote his own Unix-like kernel in 1991. To demonstrate his

understanding of systems programming.

Released as open source in 1992.

Named by his friend/file host.

Tux

The Linux Kernel mascot is a penguin named 'Tux'.

It was chosen by the Linux Benevolent Dictator for Life.

Choosing a mascot

In early 1996 people were discussing the need to a logo for Linux.

Several ideas were suggested.

Why A Penguin?

“Ok, short version:“I've always liked penguins, and when I was in

Canberra a few years ago we went to the local zoo with Andrew Tridgell (of samba fame). There they had a ferocious penguin that bit me and infected me with a little known disease called penguinitis. Penguinitis makes you stay awake at nights just thinking about penguins and feeling great love towards them. So when Linux needed a mascot, the first thing that came into my mind was this picture of the majestic penguin, and the rest is history.”

Early Linux Growth

Red Hat founded in 1993 selling their own distribution and technical support, currently making half a billion dollars a year.

Unix used to be the major web server operating system, but now Linux is widely used as a web server.

Throughout the 90s there was massive improvements in usability and a wide growth in the number of programs for Linux.

Who Uses Linux?

I am not joking or trying to be trite, but the answer to this question is: every single person in the modern world every day. Everyone who searches Google, picks up a phone and uses telecommunication infrastructure, watches a new televisions, use a new camera, makes a call on many modern cell phones, trades a stock on a major exchange, watches a weather forecast generated on a supercomputer, logs into Facebook, navigates via air traffic control systems, buys a netbook computer, checks out at a cash register, withdraws cash at an ATM machine, fires up a quick-boot desktop (even those with Windows), or uses one of many medical devices; the list goes on and on.

-Jim Zemlin, the executive director of The Linux Foundation

Current Linux Growth

By the 21st century Linux distributions began to clearly focus on ease of use and ease of install.

Mandrake/Mandriva Linux was the easiest to install and use in the early part of this century.

Currently, Ubuntu Linux is the easiest to install with only 6 questions before install begins: Including: language, name, time zone, keyboard,

confirm hard drive, ready to install?

Blue Linux

Red Linux

Two Linux

One Linux

Mark Shuttleworth

Mark Shuttleworth is a South African entrepreneur.

Lives in London, UK

Was the second space tourist.

Was a Debian Developer in the 1990s.

Ubuntu

Mark Shuttleworth founded Canonical Ltd in 2004 to develop Ubuntu.

Ubuntu would focus on ease of use.

An African word meaning 'Humanity to others', or 'I am what I am because of who we all are'.

Is a down stream distribution of Debian.