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Introduction to Linux

Contents

Introduction

History of Linux

Concepts to be known

Ubuntu 14.04 LTS setup

A free Unix-type operating system developed under the GNU General Public License.

Open source

Popular

Support most of the platforms available

Linux

History of Unix OSThe Unix OS was developed (based on Multics & CTSS

operating systems) by Ken Thompson at the AT&T Bell

Laboratories in 1969. He wanted to create an multi-user

operating system to run “space wars” game.

Ken’s philosophy was to create an operating system

with commands or “utilities” that would do one thing

well (i.e. UNIX). Pipes could be used combine

commands...

History of Unix OSThe first versions of UNIX were written in

“machine-dependent” program (such as PDP-7).

Ken Thompson approached Dennis Ritchie,

developer of C language, and in 1973 they

compiled UNIX in C to make operating system

“portable” to other computers systems.

UNIX Features

The Unix OS is a multi-user OS allowing more

that more person to directly communicate with the

computer.

Although the OS can only work on one task at a

time, a small piece of time (time slice) is dedicated

to each task/user –this referred to as “time-sharing”

Illustration of

Time-Sharing

TIME

User 1

User 2

User 3

User 4User 5

User 6

User 7

User 8

Development of Unix OS

Unix became a popular OS among institutions such as

colleges & universities through a 4-year “try before you

buy” deal.

− Efficient and inexpensive way of networking

− promotes Internet use and file-sharing

− Open system allows for source code to be shared among many

programmers - allows for better coordination among

programmers

Development of Unix OS

Students at University of California (in Berkley)

further developed the UNIX operating system

and introduced the BSD version of UnixUnix

Bell Labs

UNIX System V (5)

Proprietary

Berkley Software Distribution (BSD)

Free

Development of Unix OS

There were versions of UNIX for the Personal

Computer (PC), such as XENIX, etc., but they

didn’t catch on in popularity until Linux was

developed in the early 90’s.

History of Linux

Linux operating system

developed by

programming student

Linus TorvaldsLinus wanted to develop

Unix-like OS just to experiment with new 386 computer at the time...

Why Linux became so popular?

Linus decided to make Linux OSsource-code for Linux Kernel open to all:

− Unlike traditional Operating Systems, anyone can modify and distribute Linux OS (as long as they distribute source code of Linux Kernel)

− “Competition among Hackers” allow code to be improved and distributed often

− Many users can spot bugs in the operating system or application if source code is “open”

Other Factors:

− PC’s have increased processing power and there has been

a noted shift from mainframes and minicomputers to PCs.

− Since Linux is a “Unix Work-alike”, this OS has a

reputation to be a very stable platform for networking

(creating at-home servers) and running / maintaining

applications.

− Agencies such as Free Software Foundation created GNU

project to provide free software.

Why Linux became so popular?

ConcernsSome people claim that “there are as many version of

Linux as there are users…”

POSIX (Portable Operating System Interface for

Computer Environments) is a government standard to

ensure consistency among different UNIX and Linux

versions.

Many versions of Linux are approaching POSIX

standard.

− Multics, AT&T Bell Lab, GE, MIT

− 1969, UNIX, Ken Thompson, Dennis Ritchie

− 1973, Rewrite UNIX with C

− Berkeley UNIX(BSD UNIX)

− Commercial productsSunOS, Solaris, HP-UX, AIX, SCO UNIX

A Short History of UNIX

A Short History of Linux

A Short History of Linux(2)

Is Linux difficult ?

Benefits of Linux:

Linux can give you:

A modern, very stable, multi-user, multitasking environment.

Advanced graphical user interface. Linux uses a standard, network-transparent

X-windowing system with a "window manager" (typically KDE or GNOME but

several are available).

The graphical desktop under Linux can be made to look like MS

Windows (or probably ANY other graphical user interface of your choice).

Dozens of excellent, free, general-interest desktop applications. These

include a range of web browsers, email programs, word processors,

spreadsheets, bitmap and vector graphics editing programs, file managers,

audio players, CD writers, some good games, typing tutor, etc.

Freedom from viruses. Linux has no viruses because it is too secure an

operating system for the viruses to spread with any degree of efficiency.

Linux is quite positively here-to-stay because of its open-source nature (Linux cannot possibly

be put out-of-business). It is a standard selected for countless projects that are not going to go

away, and some of them are quite "mission-critical." Try the International Space Station, for

which Linux is the operating system (http://www2.linuxjournal.com/lj-

issues/issue59/3024.html).

In a nutshell, the GNU General Public Licence (GPL) allows anybody

to:

use the software at no charge, without any limitations,

copy, and distribute or sell unmodified copies of the software in the

source or binary form,

use the software with propriatory (e.g., your own) modifications, free of

charge, as long as you do not distribute or sell the modified version,

modify, and distribute or sell a modified version of the software as long

as the source code is included and licenced on the same terms as the

original you received (the GPL),

sell support for the software, without any limitations.

What the GPL license *does not* allow code recipients to do is to take somebody elses software licenced under GPL, modify the software, and then distrubute a this modified version of the software under a propriatory licence. Speaking plainly, the GPL licence just forbids stealing existing (somebody else's) software for incorporation into a closed, commercial-only product.

A Linux distribution, often simply distribution or distro, is a member of the Linux family of Unix-like computer operating systems.

Distros mainly based on ‘Look and Feel’ and Applications

Linux Distros

： Distros:

Red Hat Fedora, Debain, SuSe,Ubuntu,

Gentoo

Windows uses letters of the alphabet to represent different devices and different hard disk partitions. Under Windows, you need to know what volume (C:, D:,...) a file resides on to select it, the file's physical location is part of it's name.

In Linux all directories are attached to the root directory, which is identified by a forward-slash, "/". - root.

For example, below are some second-level directories:

File System

• /bin System binaries, including the command shell

• /boot Boot-up routines

• /dev Device files for all your peripherals

• /etc System configuration files

• /home User directories

• /lib Shared libraries and modules

• /lost+found Lost-cluster files, recovered from a disk-check

• /mnt Mounted file-systems

• /opt Optional software

•/proc Kernel-processes pseudo file-system

• /root Administrator’s home directory

• /sbin System administration binaries

•/usr User-oriented software

• /var Various other files: mail, spooling and logging

man info command –helpForums.

Linux Help

− The “-k” option

man –k print

− Manual pages are divided in 8 sections:

User commands

System calls

Libc calls

Devices

File formats and protocols

Games

Conventions, macro packages and so forth

System administation

− To select correct section, add section number:

man 1 passwd, man 5 passwd

man command

info command

A program for reading documentation, sometimes a replacement for manual pages

Example : info ls

Ubuntu

What is it?

Ubuntu is a Linux-based Operating System that is

open sourced (free)

Pronounced (oo-BOON-too)

Strong focus on usability and ease of installation

Why that name?

Ubuntu is an African concept meaning “humanity

toward others”

Sponsored by Canonical Ltd. Owned by South African

billionaire Mark Shuttleworth

Why use it?

Huge group of “free software proponents” (open

source)

Ubuntu is free

Alternate to Windows and MAC OS’s

Ubuntu is most popular Linux-based OS in the

world (8 million now)

Dell now offers desktops with Ubuntu

Last version – Feisty Fawn 7.04

Latest version – Gusty Gibbon 7.10

Next version – Hardy Heron 8.04 in 2011

256 KB RAM

4 GB hard drive space

Can be dual booted with current OS or used from a

live CD

Gutsy Gibbon Software Includes:

Firefox browser

Thunderbird and Evolution e-mail

Open Office suite

GIMP (Photoshop-like)

Music and Video players

Games

Summary

Pro –

Open source (free too)

Upgrade available about every 6 mo.

Compatible with MS programs

Many add-ons available

No key codes, activation, registration

Summary

Con’s

No tech support (Internet groups only)

Not all programs compatible

Drivers for peripherals not always available

How to get Ubuntu

Three ways to acquire:

1. Download from the Internet

www. Ubuntu. Com

Warning: about 600 MB download

2. Send for a free CD

Links :http://en.wikipedia.org/wiki/Unixhttp://en.wikipedia.org/wiki/LinuxDownload Source Code from:http://www.kernel.orgBooks:Unix User Guide – Rebecca ThomasYour UNIX: The Ultimate Guide-Sumitabha Das

Thank you