Linux and the Internet

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Chapter

An Introduction to Linux




What is Linux


One of the fastest growing operating system
today


Unix
-
like operating system


Named after Linus Torvalds (creator)


Linu
s + Uni
x

=
Linux


Powerful


Speed and reliability


Runs on many different types of hardware


For most part it is free or so far inexpensive
compared to Microsoft

What is so special about Linux.


Linux is said to be:


Reliable.


Simple.


Free!


Runs on a variety of platforms.


considered the most important free
software achievement.


Able to turn any 80386 or better PC into a
workstation.

What’s With The Penguins?


Linus Torvalds is a naturalists and he
always liked penguins

Unix
-
Linux Origin


Unix



Originally developed at AT&T as a multitasking
system for minicomputers and mainframes in the
1970’s.


Linux


Developed primarily be Linus Torval.


Inspired by Minix.


Kernel uses no code from AT&T or any other
proprietary source.


Developed by a group of volunteers, primarily in
the Internet, who exchange code, report bugs and
fix problems.

Linux History


First posted on the Internet: in October 1991


Linux 1.0 was released in 1994 and Linux 2.2
in 1999


Today Linux runs on millions of computers
with thousands of programmers improving it
continuously and sharing the code with
others

The GNU Project


Launched in 1984 to develop a completely Free Unix
-
like operating system: The GNU System. Many
flavors of the GNU system are currently in use, i.e.
Caldera, Redhat, Corel, etc.


These GNU Systems use the Linux Kernel, these
systems are incorrectly called "Linux", they should be
called GNU/Linux systems.


GNU is "Copylefted". Copyleft uses copyright law in
reverse. It allows software to be used, modified, and
distribute modified versions. Modified versions may
not add restrictions of their own.


Visit
www.gnu.org

for more information.

What is so special about Linux.


Linux is said to be:


Reliable.


Simple.


Free!


Runs on a variety of platforms.


considered the most important free
software achievement.


Able to turn any 80386 or better PC into a
workstation.

Linux Strengths


Powerful


Networking and e
-
business capabilities


associated with Apache Web Server


Reliable


Free to download


or affordable through distribution CDs

Linux Reservations


Linux is still primarily a network
operating system intended for servers


There are versions intended for clients now
being released


Linux is not as user friendly compared
to Microsoft operating systems


Users must learn commands to harness
the full benefits of Linux

LINUX


Features:


Complete multitasking, multiuser OS.


Compatible with Unix standards.


Supports virtual consoles.


Supports various file systems for storing data.


Provides complete implementation of TCP/IP
networking software.


Include device drivers for many Ethernet cards.

LINUX


Features (cont.)


Kernel


is developed to use protected
-
mode features of Intel
80386 and better processors.


supports demand
-
paged and loaded executables.


supports copy
-
on
-
write pages.


Linux can coexist with other OS on the same
machine.

Typical Uses of Linux


Server


Web servers and firewall


Dedicated Print servers and File servers


Used as an operating system on less
powerful hardware


Desktop


Desktop versions are now being made
available (Workstation edition of Red Hat)


Many desktop applications exist today


More are being quickly developed

Linux Application Areas


Not only the enthusiasts


ISP (Internet service providers)


Engineering companies


Retail


Publishing


Financial


Healthcare


……..and more

Linux Based Network


Linux Interface with the
Hardware


Unix
-
like


Kernel: the part of
the operation system
that interacts with
the hardware


Shell: the part of the
operating system
that interacts with
the user

Hardware

Kernel

Shell

User

Linux Implementations with
GUI

Hardware

Kernel

Shell

GUI

User

GNU/Linux K Desktop
Environment


KDE is a powerful GUI desktop environment for
Unix workstations.


Provides ease of use, contemporary functionality,
and the technological superiority of the Linux OS.


KDE is an internet project that is "Open" in every
sense.


All KDE sources are open to everyone and may be
distributed by anyone subject to the well know GNU
licenses.


KDE is a mature desktop suite.


Visit
WWW.KDE.ORG

for further information.

Current KDE Distribution

Includes the following packages:


KDE
-
Libs: Various Run
-
time libraries


KDE
-
Base: The base components


KDE Graphics: e.g. Kpaint, Kfax, Kghostview


KDE Utilities: Kedit, KCalc, Knotes


KDE
-
Multimedia: KMidi, Kmodplayer,
Kmixer, KSCD


KDE
-
Games: Kasteroids, Kpat, Ktetris


KDE
-
Admin: Various rools to aid system
administration

Current KDE Distribution

Includes the following packages:


KDE
-
Network: Kppp, Krn, Kmail


Most current distributions of Linux Use
a modified version of KDE. Corel calls
its version Enhanced KDE.


Visit Linux.Corel.com, Linux.com,
Linuxworld.com for more information.


Demonstration.

Linux Directory Structure (/)


The Linux TCP/IP
Networking Layers

BSD Sockets

INET Sockets

UDP

TCP

IP

PPP

SLIP

Ethernet

Network Application

User

Kernel

Socket
Interface

Protocol
Layers

Network
Devices

ARP

Obtaining the Linux Operating
System


By downloading from websites


Purchasing from a computer retail store


Obtaining sources from Linux related
magazines

Some Linux Vendors and their
Websites


Caldera OpenLinux 2.3


http://www.calderasystems.com/



Corel


http://linux.corel.com



Mandrake


http://www.linux
-
mandrake.com/en/



Red Hat


http://www.redhat.com



know for its package manager


Perhaps the most popular site

Linux Related Websites


General Linux Websties


http://www.linux.org


http://metalab.unc.edu/mdw/index.html


Linux in business


http://www.linux
-
business.com


http://www.linuxresources.com


Linux Technical Websites


http://www.slashdot.org


http://www.linuxbase.com

Module

Linux Vs Windows

Licensing and Code Ownership

Linux


open
-
source
community


couple of vendors


Manufacturer

Licensing Fee

Linux

No


Windows 2000

Microsoft

Windows 2000

Yes

Installation Ease

Linux


getting easier


but still more than
Windows 2000


Windows 2000

because of the experience of
previous versions, it’s very
easy to install and setup

automated software setup
over a network

User Interface

Linux


DOS
-
like
command
-
line


Newer versions
have GUI interfaces
such as Gnome and
KDE


Windows 2000

GUI
-
based

Availability of Applications

Linux


few existing applications
for Linux


more and more
applications are written
for running on Linux but
not mainstream yet. (e.g.
support by IBM)


Windows 2000

many applications are
available



Reliability

Linux


good


many users report
that it can be run for
months without
crashing

Windows

2000


Good


Reliability has
improved over the
years


Anticipated Growth in Market Share

Market Share
for Server OS,
1998 vs. 1999

Future of Linux

Reasons for growth


the undercurrent of dissent against Microsoft
(i.e. as an alternative to the Windows O/S)


Competing vendors such as Sun promoting
the Linux operating system


ability to modify the source code


control and freedom for the power user


easy to obtain

Module

Major Linux Features

Office and Email Applications


Office Applications


Ex: StarOffice, Koffice, Applixware and
Corel Wordperfect


Email Clients


Ex: kmail, spruce, netscape and mozilla

Video and Audio


Graphic Editors & Manipulators


Ex: The GNU Image Manipulation Program(GIMP)


Audio, Video and DVD


Video clips compact player
-
xanim


Mpeg player
-
gtv, mtv


DVD player
-
Livid


MP3 player
-
mpg123


Voice Recognition


Xvoice works on any X11 application


CvoiceControl is used on Linux console

Internet Applications


Internet Browsers


Ex: Netscape


Internet Chat


Ex: Xchat


Web Page Editors


Ex: Amaya


Network Protocols Supported


TCP/IP


IPv6


IPX/SPX


AppleTalk Protocol Suite


PPP, SLIP, PLIP


Amateur Radio

Internet Servers and Browsers
for Linux


Mail Server


Sendmail


Web Servers


Apache


Web Browsers


Netscape Navigator

Internet Services Supported


FTP Servers and clients


News Services


Domain Name System


DHCP


NIS


Authentication

Remote Execution of
Applications


Telnet


The X Windows System

Security Issue


Web Server Attacks


Weak Passwords


Denial of Service Attacks


Man in the Middle Attack


IP Address Spoofing


Network Snooping


Impersonation


Sample Web Servers for Linux


Apache server


Perhaps the most popular web server for Linux


NCSA HTTPd


http://hoohoo.ncsa.uiuc.edu


Netscape Fast Track Server


AOL server


http://www.aolserver.com/server


iPlanet Web Server


etc.

Apache Server


Developed by NCSA in 1995


Apache and its source code is free


Runs on Unix and Linux


Supports HTTP 1.1


Apache Strengths


High market share


Over 57% web sites are using Apache


Flexible


Available free of charge

Apache Weakness


Performance


should create portable code for its OS


Fully guided GUI based installation is
yet to materialize


Few application services

Apache vs. IIS: A Quick
Comparison


Apache

IIS

SQL Database Interaction

Perl, PHP

ASP

GUI Installation

On developing

Yes

Cost

Low

High

Management tools

Poor

Good

Steady as load increased

Good

Poor

Built search engine

No

Yes

Flexibility

High

Low

Market share

High

Lower than Apache


Top Server

Source : Netcraft web server survey

Linux SQL Database (Free)


MySQL


a true multi
-
user, multi
-
threaded SQL database
server


a client/server implementation


PostgreSQL


a sophisticated Object
-
Relational DBMS


Supports almost all SQL constructs


GadFly


a very small, fast and highly portable database
system


support a large subset of ODBC 2.0 SQL

MySQL Implementation
Example

MySQL

Server

PHP

Apache

Web
page on
browser

PHP

script

Web Research


Visit the Red Hat and the Mandrake
website at the following addresses to
obtain additional information


www.redhat.com



http://www.linux
-
mandrake.com/en/


Module

Linux Multimedia

Audio Mixer and Sound Player



AuMixer

Console
-
mixer tool.

http://jpj.net/~trevor/aumix.html



B
-
play

Sound player, pretty good.

ftp://sunsite.unc.edu/pub/Linux/apps/sound/pla
yers/



Synathesia

You just can't live without this program! Is a 'visual'
CD player. It's just a SVGAlib CD player that shows
some nice effects while playing
ftp://sunite.unc.edu/pub/Linux/apps/sound/light
show/


More on CD Players


WorkMan

A VERY nice XView CD player.

ftp://sunsite.unc.edu/pub/Linux/apps/sou
nd/cdrom/X/



MikMOD

Regular MOD player, plays most of the MOD
-
file
types
-

in the way YOU wish. You can also get a X
-
Interface

http://www.tohs.abacom.com/mikmod/



MiXViews

A full featured sound recording / editing program.
Does everything and more. You have many effects
and so on. I only find some disabilities: bugs (a few),
no "dynamic" recording, not so many file formats,
ugly GUI.

http://www.ccmrc.ucsb.edu/~doug/htmls/MiXVie
ws.html


MOD Player and Sound
Recording

More on Sound Recorders


X
-
Wave

A sound recorder / player.

Get it NOW at:

ftp://sunsite.unc.edu/pub/Linux/apps/sound/edit
ors/

Related:


http://www.filefarm.com/filefarm/linux/subje
cts/524/


http://eunuchs.org/linux/frames.html


http://eunuchs.org/linux/scanner/index.html


http://eunuchs.org/linux/ip_masq/index.html




Mpeg 1 Layer 3 (mp3) Tools


A mp3 encoder and a decoder, for making
your own mp3 files / tweak with someone
elses. Do I need to say anything more? And,
ther's some other tools at the same homepage.

http://www.mpeg3.org/main.html




sPlay

MPEG 3 Audio player.

http://adam.kaist.ac.kr/~jw95/


MPEG

Audio Editor


Multitrack


Multitrack is a SVGAlib digital audio editor.
It'll soon come out in a 2.0 version. It's too
bad it's not X
-
based. Another irritating thing
is that you must create the WAVE files that
you are going to record before you can
record.
http://rulhmpc38.leiden.univ.nl/private/mu
ltitrack/multitrack.html



Rosegarden

And now! That all of you been waiting for! A
MIDI program that works! It have a
notationing system and so on! Perfect!
Nothing to complain about...yet!
http://www.bath.ac.uk/~masjpf/rose.html



Playmidi

A general MIDI player.

ftp://sunsite.unc.edu/pub/Linux/apps/sou
nd/players/

MIDI


X
-
Anim

A animation player for X, plays many,
MANY formats.

http://smurfland.cit.buffalo.edu/xanim/ho
me.html


Animation Player


XView Mpeg

A XView based mpeg movie player.

/pub/Linux/apps/graphics/viewers/X/




MPEG Movie Player

End of Chapter

THANK YOU