2. Presentation layout
• History
• Why Linux
• Role of Linux
• Linux internal
• Adoption and popularity
• Day to day Usage
• Conclusion
3. Before LinuxBefore Linux
• In 80’s, Microsoft’s DOS was the dominated OS for
PC
• Apple MAC was better, but expensive
• UNIX was much better, very expensive. Only for
minicomputer for commercial applications
• Reliable, multiuser & multi-programming env.
• People were looking for a UNIX based system, which
should be cheaper and can run on PC
• Both DOS, MAC and UNIX were proprietary, i.e., the
source code of their kernel is protected
• No modification is possible without paying high
license fees
5. • Developed in 1991 by a University of Finland student Linus Torvalds.
• Basically a kernel, it was combined with the various software and
compilers from GNU Project to form an OS, called GNU/Linux
• Linux is a full-fledged OS available in the form of various Linux
Distributions
• RedHat, Fedora, SuSE, Ubuntu, Debian are examples of Linux distros
• Linux is supported by big names as IBM, Google, Sun, Novell, Oracle, HP,
Dell, and many more
What is Linux?
6. History
Wrote the GNU manifesto in 1985 outlining philosophy
Software that is free means more than free of charge
"It means that much wasteful duplication of system programming effort
will be avoided. This effort can go instead into advancing the state of
the art."
By early 1990s many of the GNU OS utilities were complete
Meanwhile....
•A famous professor Andrew Tanenbaum developed Minix,
a simplified version of UNIX that runs on PC
•Minix is for class teaching only. No intention for
commercial use
•Linus Torvalds started work on the Linux Kernel
First version released in 1991
Changes Linux to GPL licence in 1992
Combined with GNU to make an OS
7. GNU projectGNU project
– Established in 1984 by Richard Stallman, who believes that
software should be free from restrictions against copying or
modification in order to make better and efficient computer
programs
GNU is a recursive acronym for “GNU's Not Unix”
Aim at developing a complete Unix-like operating system
which is free for copying and modification
Companies make their money by maintaining and
distributing the software, e.g. optimally packaging the
software with different tools (Redhat, Slackware,
Mandrake, SuSE, etc)
Stallman built the first free GNU C Compiler in 1991. But
still, an OS was yet to be developed
9. Free, Libre, Open Source Software
(FLOSS)
• What can you do?
– Freedom to use
– Freedom to examine
– Freedom to redistribute
– Freedom to modify
• What can't you do?
– Deny these freedoms to anyone else
10. • Linux is free and always will be as compared
to the very costly Windows and Mac OSX
• Using pirated Windows is a bad thing
Linux is Free
11. • Security has always been the number one
priority with Linux
• Linux has a robust security system
• Least affected platform,
– Malware developer are negligible compared to
problem fixture.
Forget about viruses.
12. • Have you ever lost your precious work because Windows crashed? Have
you ever gotten the "blue screen of death" or error messages telling you
that the computer needs to be shut down for obscure reasons?
• Crashes or freezes are not prevalent in Linux
Is your system unstable ?
13. • When the system has installed, why would you still need to install
stuff ?
• Common software such as music player, web browser, video player,
image editor, PDF reader, chat messenger, office apps
Linux comes with software built-in
14. • Just like Windows’ Update tool, Linux has a more better
alternative to it to update all your system in a few clicks
Updating in a single click
15. • As Linux is impervious to viruses, trojans,
spywares, which are the main reasons to slow
down the PC, systems based on it do not get
slower
• Linux consumes lesser system resources
Linux does not get slow
16. • If you already know what fragmentation is,
and are already used to defragmenting your
disk every month or so, here is the short
version : Linux doesn't need defragmenting.
• Whereas Windows-based system get
fragmented frequently and need attention in
this regard.
Linux does not need defragmentation
17. • Linux runs perfectly well on older hardware,
on which Windows XP would probably even
refuse to install, or let you wait 20 seconds
after each click
• Windows requires more and more hardware
power as its version number increases (95, 98,
2000, Me, XP, etc.). So if you want to keep
running Windows, you need to constantly buy
new hardware
Linux can run on older hardware
18. • With Linux, everything is much simpler. Linux
has what is called a "package manager": each
piece of software is contained in its own
"package". If you need some new software,
just open the package manager, type a few
keywords, choose which software you want to
install and press "Apply" or "OK". Or you can
just browse existing software (that's a lot of
choice!) in categories.
Add new software in a few clicks
19. • Due to the various options available in Linux,
like a lot of DEs, themes, Window Managers,
and the modular nature of DEs, Linux is very
customizable
• The extent of customizability is clearly implied
by the fact that some people have gone as far
as to customize their Linux OS to make them
look and feel like Mac OSX and Windows
Linux is extremely customizable
20. No threat of viruses
Linux systems are extremely stable
Linux is Free
Linux comes with most of the required software pre-installed
Update all your software with minimum fuss
Linux never gets slow
Linux does not need defragmentation
Linux can even run on oldest hardware
Adding more software is a matter of a few clicks
Most Windows-only apps have either their native version or
alternatives for Linux
With Linux, you get the highest degree of possible customizability
Why Linux: Summary
21. 21
Roles of Linux
• Desktop
• Server
• Linux for application developer & embedded
system developer
22. • Can be controlled through command-line (CLI) or Graphical User Interface
(GUI)
• GUI run through Desktop Environments (DE)
• KDE, GNOME, Xfce, E17 are popular DEs
• The GUI interface is easy-to-use and much like that of Windows and Mac
OSX
• The CLI is similar to that of UNIX/BSD
Linux User InterfaceLinux User Interface
23. 23
Linux on the Desktop
• First, there has been a historical lack of
desktop productivity applications available for
Linux.
• The second issue is that the average user
tends to find Linux somewhat intimidating.
24. Generic use of Linux
• Document preparation
– Presentation
– Word document
– Excel worksheet
• PDF document preparation
– Latex (complete report preparation tool)
• Inbuilt PDF viewing tools kpdf, gpdf etc
• Diagram preparation and storing them in multiple formats (fig, dia
tools)
• Text file preparing and editing
• Printing (network/standalone)
• Web browsing
• There is single interface to call & exit any tools---- i.e. terminal
25. • It is possible to install/run Windows software on Linux
• Wine helps run a wide range of Windows applications
• Cedega helps run huge number of Windows games flawlessly
• Cygwin helps to run linux applications in windows
Running Windows software on Linux
and vice versa
26. • Many native games are available, both 3D and 2D
• Wine and Cedega help run Windows-only games
• Popular games for Linux are: Quake, Unreal Tournament, Counter Strike,
Doom, Cube, CodeRED, Wesnoth, OpenArena, SuperTux, Frozen Bubble,
Medal of Honor, and many more.
Gaming on Linux
27. 27
Linux as a Server..
■ Web Server Linux is also widely deployed as a
Web server. The most popular Web service
currently used on Linux is the Apache Web
server.
■ E-Mail Server There are a variety of different
e-mail services available for Linux that can
turn your system into an enterprise-class e-
mail server.
28. Professional use of Linux
• Embedded system development
– Texas instrument platform
– All ARM based microcontroller
– Intel based platform
– PowerPC, ARM etc
• Desktop applications (equivalent to windows)
• Possible available Linux Kernels
– RT Linux
– Montavista Linux
– ucLinux etc.
• VLSI tools
29. • Modern languages are cross-platform, like Python, Ruby, Perl, Java
• Most Linux distros support these languages and have their runtimes pre-
installed
• GTK+ and Qt are widely used to design applications for Linux
• IDEs like NetBeans, Anjuta, KDevelop, MonoDevelop, Eclipse are available
for Linux too
Programming in Linux
30. How to learn commands
• Primary – man(manual) pages.
• man <command> - shows all information
about the command
• <command> --help - shows the available
options for that command
• Secondary – Books and Internet
31. Important commands
• File handling
– mkdir, ls, dir, cd, pwd, cp, rm, mv,
– find [OPTION] [path] [pattern], history, locate
• Text processing
– Cat file1.txt file2.txt
– Grep –I apple sample.txt
– Wc –L xyz.txt for number of new lines, words, bytes
– Sort lines of text file
• File permission & ownership
– Chmod, chown, su, passwd, who etc.
32. Important commands…
• Process management
– Ps, kill, top
• Archival
– tar --cvf /home/archive.tar /home/original
– zip [OPTION] DEST SOURCE
– unzip original.zip
• Network related
– ssh -X guest@10.105.11.20
– scp [options] [[user]@host1:file1] [[user]@host2:file2]
33. Important commands…
• File system
– mount /dev/sda5 /media/target
– umount /media/target
– du – estimate file space usage
– df – report filesystem disk space usage
– quota – display disk usage and limits
– reboot – reboot the system
– Shutdown –h now
34. Linux ShellLinux Shell
Shell interprets the command and
request service from kernel
Similar to DOS but DOS has only one
set of interface while Linux can select
different shell
– Bourne Again shell (Bash), TC shell
(Tcsh), Z shell (Zsh)
Kernel
Bash, Tcsh, Zsh
ls pwd
whoami
Different shell has similar but different functionality
Bash is the default for Linux
Graphical user interface of Linux is in fact an application
program work on the shell
36. • /bin Essential user command binaries that need to be available
also in single user mode.
• /sbin Essential system binaries (e.g. init, insmod, ifup)
• /lib Libraries for the binaries in /bin and /sbin
• /usr/bin Non-essential user command binaries that are not needed
in single user mode
• /usr/sbin Non-essential system binaries (e.g. daemons for network-
services)
• /usr/lib Libraries for the binaries in /usr/bin and /usr/sbin
• /etc Host-specific system-wide configuration files
• /dev Device files
• /home User home directories (optional)
• /proc Virtual file system documenting kernel and process status
as text files
36
38. Desktop applications…
• Text editor(vi, vim, gedit, nedit, kedit etc)
• GUI based application development using QT
or Java
• Works as Embedded System development
Host
• Removable media handling as easy as in
windows
50. • Linux is the most used OS on servers
• 5 out of 10 reliable web hosting companies use Linux
• Linux is the cornerstone of the LAMP server-software combination (Linux,
Apache, MySQL, Perl/PHP/Python) which has achieved popularity among
developers
• Out of top 500 supercomputers, Linux is deployed on 426 of them
Linux on Servers and Supercomputers
51. • 16.7% of smartphones worldwide use Linux as OS
• Linux poses a major competition to the most popular OS is this segment –
Symbian
• Nokia, Openmoko supply Linux on their select smartphones
Linux on Embedded Systems
53. 1983 (September): GNU project was announced publicly
1991 (September): first version of the Linux kernel was released to the Internet
2001 (second quarter): Linux server unit shipments at 15% annual growth rate
2004: Linux shipped on approximately 50% of the worldwide server blade units,
and 20% of all rack-optimized servers
2005: Microsoft representatives accuse Brazilian college using Famelix of pirating
Microsoft Windows
2007: Dell announces it will ship select models with Ubuntu Linux pre-installed
2007: Lenovo announces it will ship select models with SUSE Linux Enterprise
Desktop 10 pre-installed
2007: HP announces that it will begin shipping computers preinstalled with Red Hat
Linux in Australia
2007: ASUS launches the linux-based ASUS Eee PC
2008: Dell announces it will begin shipping Ubuntu based computers to Canada and
Latin America
2008: Dell is shipping systems with Ubuntu pre-installed in China
2008: Acer launches the linux-based Acer Aspire One
Adoption of Linux
54. • Governments of many countries around the
world are shifting to Linux from Windows due
to the many benefits it offers
• Countries like India, France, Pakistan, Czech
Republic, Brazil, Germany, USA, Austria, Spain,
China, and Peru already use Linux
Adoption by Governments
55. • The widely popular OLPC (One Laptop Per
Child) Project’s XO Laptop runs on Linux
• Universities in countries, like USA, Germany,
Netherlands, Philippines, Brazil, Russia,
Switzerland, India use Linux on their
workstations and servers
Linux in Education
56. 56
Linux Distributions
• Today there are hundreds of different distributions
available popular Linux distributions include
■ SUSE Linux TurboLinux■
■ Fedora Linux Mandrake Linux■
■ Red Hat Enterprise Linux Lycoris Linux■
■ Debian Linux
■ CentOS Linspire■
■ ALT Linux
■ Gentoo Linux Ubuntu■
■Slackware Linux
57. Demonstration
• USB handling
• File browsing, copying, deletion, searching
• Office document preparation
• Text file preparation and editing
• Usage of photo editor
• Usage of multimedia players
• Diagram/figure preparation
• Network browsing
• Usage for software developer
– C/C++/Java/QT usage
58. Concluding Remarks
• Grown-up and matured OS – Still numerous
development is on
• Capturing mobile market & Embedded platforms
• Gaining popularity in every domain among all
types of users
• More secure and GUIs comparable to Mac &
Windows (Ease of use for layman too)
• Supports Open Source Movement
• Customizable – Freedom to Developer & User
60. What is Linux?
Linux is a free Unix-type operating system
originally created by Linus Torvalds developed
under the GNU General Public License and
the source code of which is freely available to
every one.
61. • Inspired by the UNIX OS, the Linux kernel was developed as a clone of
UNIX
• GNU was started in 1984 with a mission to develop a free UNIX-like OS
• Linux was the best fit as the kernel for the GNU Project
• Linux kernel was passed onto many interested developers throughout the
Internet
• Linux today is a result of efforts of thousands of individuals, apart from
Torvalds
History of Linux
62. Why Linux
• Use of open source Linux mean zero penny for license
• At any point of time, Linux community is available to help
• Reliable operation of computer
• Multi programming and multi user environment
• Very less prone to virus/malware and cyber attack [Antivirus may
not be needed for desktop]
• Recompile/ reconfigure Linux tools as per your need [./configure,
make & make install]
• Same Linux box can be used for server as well Desktop applications
• Very secure file system so data can not be seen by another user
• Online help of any command you may wish to use
63. The most important subdirectoriesThe most important subdirectories
inside the root directory are:inside the root directory are:
• /bin : Important Linux commands available to the average user.
• /boot : The files necessary for the system to boot. Not all Linux
distributions use this one. Fedora does.
• /dev : All device drivers. Device drivers are the files that your Linux
system uses to talk to your hardware. For example, there's a file in the
/dev directory for your particular make and model of monitor, and all of
your Linux computer's communications with the monitor go through that
file.
• /etc : System configuration files.
• /home : Every user except root gets her own folder here, named for her
login account. So, the user who logs in with xyz, has the directory
/home/xyz, where all of her personal files are kept.
• /lib : System libraries. Libraries are just bunches of programming code
that the programs on your system use to get things done.
64. The most important subdirectoriesThe most important subdirectories
inside the root directory are:inside the root directory are:
• /mnt : Mount points. When you temporarily load the contents of a CD-
ROM or USB drive, you typically use a special name under /mnt. For
example, many distributions (including Fedora) come, by default, with the
directory /mnt/cdrom, which is where your CD-ROM drive's contents are
made accessible.
• /root : The root user's home directory.
• /sbin : Essential commands that are only for the system administrator.
• /tmp : Temporary files and storage space. Don't put anything here that
you want to keep. Most Linux distributions (including Fedora) are set up
to delete any file that's been in this directory longer than three days.
• /usr : Programs and data that can be shared across many systems and
don't need to be changed.
• /var : Data that changes constantly (log files that contain information
about what's happening on your system, data on its way to the printer,
and so on).
65. • Linux is desktop computer ready
• Large number of distros targeted at Desktop users are available
• Linux desktop distros come with many commonly used pre-installed
softwares
• The modern Linux interface is user-friendly and makes the interaction
with computer easy
Linux on the Desktop
66. Linux TodayLinux Today
– Linux has been used for many computing
platforms
– PC, PDA, mobiles to Supercomputer,…
– 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, Slackware, etc
67. • Linux can be used on a wide range of
electronic devices, like PC, PDAs,
Smartphones, iPods, MP3 Players, PlayStation
2 & 3, mission critical servers and so on…
Linux on other devices
68. 68
Commonly Used CLI Commands
and Utilities
/ : denote root directory
./ : denote current directory
PATH :
■ halt This command shuts down the operating
system, but can only be run by the root user.
■ reboot This command shuts down and
restarts the operating system. It also can only
be run by root.
69. 69
Commonly Used CLI Commands
■ init 0 This command also shuts down the
operating system, and can only be run by your
root user.
■ init 6 This command also shuts down and
restarts the operating system. It also can only
be run by root.
■ man: is help command. Ex: man ls
70. 70
Commands…
■ su (super user) This command switches the
current user to a new user account. This
command is most frequently used to switch to
the superuser root account. In fact, if you
don’t supply a username, this utility assumes
that you want to change to the root account.
If you enter su -, then you will switch to the
root user account and have all of root’s
environment variables applied.
71. 71
Commands…
■ env This command displays the environment
variables for the currently logged-in user.
■ echo This command is used to echo a line of
text on the screen. It’s frequently
used to display environment variables.
Ex: echo $PATH
72. 72
Commands…
■ top This command is a very useful
command that displays a list of all
applications and processes currently
running on the system.
■ which This command is used to display the
full path to a shell command or utility.
Ex: which ls
It display: /bin/ls
73. 73
Commands…
■ whoami This command displays the username of the
currently logged-in user.
■ netstat This command displays the status of the
network, including current connections, routing tables,
etc.
■ route This command is used to view or manipulate the
system’s routing table.
■ ifconfig This command is used to manage network
boards installed in the system. It can be used to display
or modify your network board configuration parameters.
75. Why linux …
• 43% of all web sites use Linux servers running
the Apache Web server
• Kernel can be customized to user’s needs
• Android uses Linux Kernel
• Apple also uses UNIX as a basis