Introduction toIntroduction toLinuxLinux

By: Ravi Prakash GiriBy: Ravi Prakash GiriCSE 2CSE 2ndnd Year Year

Shri Mata Vaishno Devi University,JammuShri Mata Vaishno Devi University,Jammu

What we will cover ?What we will cover ? IntroductionIntroduction What is Linux?What is Linux? Linux Linux

DistributionDistribution Linux vs. Linux vs.

WindowsWindows Process of Process of

Installing LinuxInstalling Linux Basic Basic

CommandsCommands Working exampleWorking example SummarySummary

UNIX-like operating system

Comprised System utilities Libraries From GNU Project Sometimes called GNU Linux

Supported by: IBM, Sun, Novell, Microsoft,…

What is Linux ?

LINUX HistoryLINUX History The UNIX operating system was born in the late The UNIX operating system was born in the late

1960s. It originally began as a one man project led 1960s. It originally began as a one man project led by Ken Thompson of Bell Labs, and has since grown by Ken Thompson of Bell Labs, and has since grown to become the most widely used operating system.to become the most widely used operating system.

In the time since UNIX was first developed, it has In the time since UNIX was first developed, it has gone through gone through manymany different generations and even different generations and even mutations.mutations. Some differ substantially from the original version, like Some differ substantially from the original version, like

Berkeley Software Distribution (BSD) or Linux.Berkeley Software Distribution (BSD) or Linux. Others, still contain major portions that are based on the Others, still contain major portions that are based on the

original source code.original source code. An interesting and rather up-to-date timeline of An interesting and rather up-to-date timeline of

these variations of UNIX can be found at these variations of UNIX can be found at http://www.levenez.com/unix/history.html.http://www.levenez.com/unix/history.html.

Before LinuxBefore Linux In 80’s, Microsoft’s DOS was the dominated OS In 80’s, Microsoft’s DOS was the dominated OS

for PCfor PC Apple MAC was better, but expensiveApple MAC was better, but expensive UNIX was much better, but much, much more UNIX was much better, but much, much more

expensive. Only for minicomputer for commercial expensive. Only for minicomputer for commercial applicationsapplications

People was looking for a UNIX based system, People was looking for a UNIX based system, which is cheaper and can run on PCwhich is cheaper and can run on PC

Both DOS, MAC and UNIX were Both DOS, MAC and UNIX were proprietaryproprietary, i.e., , i.e., the source code of the source code of their kernel is protectedtheir kernel is protected

No modification is possible without paying high No modification is possible without paying high license feeslicense fees

Beginning of LinuxBeginning of Linux

A famous professor Andrew Tanenbaum A famous professor Andrew Tanenbaum developed developed MinixMinix, a simplified version of UNIX , a simplified version of UNIX that runs on PCthat runs on PC

Minix is for class teaching only. No intention Minix is for class teaching only. No intention for commercial usefor commercial use

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

Red Hat Linux : One of the original Linux distribution.The commercial, nonfree version is Red Hat Enterprise Linux,

which is aimed at big companies using Linux servers and desktops in a big way.

Free version: Fedora Project.

Debian GNU/Linux : A free software distribution. Popular for use on servers. However, Debian is not what many would consider a distribution for beginners, as it's not designed with ease of use in mind.

SuSE Linux : SuSE was recently purchased by Novell. This distribution is primarily available for pay because it contains many commercial programs, although there's a stripped-down free version that you can download.

Mandrake Linux : Mandrake is perhaps strongest on the desktop. Originally based off of Red Hat Linux.

Gentoo Linux : Gentoo is a specialty distribution meant for programmers.

Linux distribution

LinuxLinux WindowsWindows

Linux has different versions, depending on which vendor develops and runs it. Linux vendors include: Linspire, Linspire, Red HatRed Hat, , SuSESuSE, Ubuntu, , Ubuntu, Mandriva, Knoppix, Mandriva, Knoppix, SlackwareSlackware, , Caldera, Caldera, DebianDebian

Windows has different versions. It started with Win3.x, Win9x, WinME, WinNT, Win2000, WinXP. It is a proprietary software produced by Microsoft.

Linux vs. Windows

LinuxLinuxCost

WindowsWindowsCostCost

Linux is cheap or free to run. It can be downloaded from various Linux vendors.

Linux may run off a server so numerous computers may have access to the program.

Windows is expensive to run. The price to purchase a full version of Windows XP Professional is about USD400. Only one copy of Windows may be used on a computer. Activation with Microsoft is needed.

Linux vs. Windows

LinuxLinuxCost

WindowsWindowsCostCost

Linux is an open source software. Source codes are freely distributed to the public, of which programmers had reviewed to improve performance, eliminate bugs and strengthen security.

Windows is a proprietary closed source software. Codes are not released to the public.

Linux vs. Windows

LinuxLinuxOS Stability

WindowsWindowsOS OS Stability

When properly configured, Linux will run until the hardware fails or if the system is shut down. Linux claims that it may continuously run up to more than a year without freezing or shutting down. It is not as prone to bugs and viruses as most are geared towards Windows.

It is known to crash easily, and be infected by bugs and viruses. .

Linux vs. Windows

Methods of InstallationMethods of Installation

Traditional booting from DVD/CDTraditional booting from DVD/CD Using third party softwareUsing third party software

i.e. making bootable USBi.e. making bootable USB

drivedrive

For making your USB For making your USB bootable,refer to the bootable,refer to the

article atarticle at

http://www.resolutiondesphttp://www.resolutiondesproblemes.blogspot.comroblemes.blogspot.com

Device: This field displays the partition's device name.

Start: This field shows the sector on your hard drive where the partition begins.

End: This field shows the sector on your hard drive where the partition ends.

Size: This field shows the partition's size (in MB).

Type: This field shows the partition's type (for example, ext2, ext3, or vfat).

Mount Point: A mount point is the location within the directory hierarchy at which a volume exists; the volume is "mounted" at this location. This field indicates where the partition will be mounted.

Partition Fields

Filesystem TypesFilesystem Types

Linux Installation

ext2 — ext2 — An ext2 filesystem supports standard Unix file An ext2 filesystem supports standard Unix file types (regular files, directories, symbolic links, etc). It types (regular files, directories, symbolic links, etc). It provides the ability to assign long file names, up to 255 provides the ability to assign long file names, up to 255 characters. Versions prior to Red Hat Linux 7.2 used ext2 characters. Versions prior to Red Hat Linux 7.2 used ext2 filesystems by default.filesystems by default.ext3 —ext3 — The ext3 filesystem is based on the ext2 filesystem The ext3 filesystem is based on the ext2 filesystem and has one main advantage — journaling. Using a and has one main advantage — journaling. Using a journaling filesystem reduces time spent recovering a journaling filesystem reduces time spent recovering a filesystem after a crash as there is no need to fsck the filesystem after a crash as there is no need to fsck the filesystem. filesystem. swap —swap — Swap partitions are used to support virtual Swap partitions are used to support virtual memory. In other words, data is written to a swap memory. In other words, data is written to a swap partition when there is not enough RAM to store the data partition when there is not enough RAM to store the data your system is processing.your system is processing.vfat —vfat — The VFAT filesystem is a Linux filesystem that is The VFAT filesystem is a Linux filesystem that is compatible with Windows 95/NT long filenames on the compatible with Windows 95/NT long filenames on the FAT filesystem. FAT filesystem.

Recommended Partitioning Recommended Partitioning SchemeScheme

Linux Installation

Unless you have a reason for doing otherwise, it is Unless you have a reason for doing otherwise, it is recommended that you create the following recommended that you create the following partitions: partitions:

/boot partition – contains kernel images and grub /boot partition – contains kernel images and grub configuration and commandsconfiguration and commands

/ partition / partition

/home partition /home partition 

Any other partition based on application (e.g Any other partition based on application (e.g /usr/local for squid)/usr/local for squid)

swap partition — swap partitions are used to support swap partition — swap partitions are used to support virtual memory. In other words, data is written to a virtual memory. In other words, data is written to a swap partition when there is not enough RAM to swap partition when there is not enough RAM to store the data your system is processing. The size of store the data your system is processing. The size of your swap partition should be equal to twice your your swap partition should be equal to twice your computer's RAM.computer's RAM.

MANDRIVA MANDRIVA INSTALLATIONINSTALLATION

Universal USB InstallerUniversal USB Installer

This tool is widely used to make USB This tool is widely used to make USB bootable for various operating bootable for various operating systems or applications.systems or applications.

Once you made your USB Once you made your USB bootable,you are ready to use it for bootable,you are ready to use it for installing Linux. installing Linux.

Basic Linux Basic Linux CommandsCommands

Commands:

/ (root directory)

/root – home directory of the user root

pwd – you can see your home directory

df – to see disk space available

cd – to change to different directory or to go back to home dir

.. - move to parent directory

ls – list the contents of a directory; Options: -l (more info)

-a (displays hidden files)

-t (sort by time)

-r (oldest first)

Example: ls –ltr : display an long list of files that are sorted by time, display the oldest ones first

Some of the basic commands you should learn are the ones that help you navigate the file system.

Directory is denoted by a / (slash) character

Executable program by a *Hidden file preceded by a . (dot)

cp : copy one file to anotherrm : remove a fileman : ask for the manual (or help) of a

commande.g. man cd ask for the manual of the

command cdcat : to show the content of a text file

e.g. cat abc.txt show the content of abc.txt

whoami : to show the username of the current user

Working ExampleWorking Example

Phishing Social Phishing Social Networking SitesNetworking Sites

BACKTRACK 5 R 2BACKTRACK 5 R 2Phishing Using LinuxPhishing Using Linux

End of End of PresentationPresentation

ThankyouThankyou!!