2. What is open source
• Open source: software and source code
available to all
– The freedom to distribute software
and source code
– The ability to modify and create
derived works
– Integrity of author’s code
3. GNU’s ( not UNIX )
• The GNU project wad started in 1983
for developing a complete Unix-like
operating system, including software
development tool and application
programs, entirely of free software
• By the release of the first version of the
Linux kernel, the GNU project had
produced all the necessary
components of this system except the
kernel
4. Linux Origins
• 1984: The GNU Project and the Free
Software Foundation
– Create open source version of UNIX
utilities
– Create the General Public License (GPL)
• Software license enforcing open
source principles
• 1991: Linus Tarvalds
– Create open source, UNIX-like kernel,
released under the GPL
5. What is LINUX
• Linux is a free Unix-type
operating system originally
created by Linus Torvalds
with the assistance of
developers around the
world.
• It originated in 1991 as a
personal project of Linus
Torvalds, a Finnish
graduate student.
6. What is LINUX
• The Kernel version 1.0 was released in
1994 and today the most recent stable
version is 2.6.9.
• Developed under the GNU General
Public License , the source code for Linux
is freely available to everyone.
7. Why Linux
You can use Linux as Server Os or as stand alone Os on
your PC. (But it is best suited for Server.) As a server Os
it provides different services/network resources to client.
Server Os must be:
• Free: A Linux Distribution has thousands of
dollars worth of software for no cost.
• Stable: The crash of an application is much less
likely to bring down the OS under Linux.
• Robust: Linux servers are often up for hundreds of
days compared with the regular reboots required with
a Windows system.
• Secure
• High Performance
8. LINUX Principles
• Everything is a file
• Ability to chain programs together to
perform complex task
• Configuration data stored in text
9. LINUX distribution
• Ubuntu
• openSUSE
• Debian
• Redhat
– Fedora
– Centos
– Redhat Enterprise Linux
• Moon OS
• Slackware
10. Why of Linux Operating System
• Open Source development model
• Supports wide variety of hardware
• No requirement latest hardware
• Supports many networking protocol
and configurations
• Speed and Stability
• Supports more file systems
11. LINUX Kernel
• The kernel is the essential center of a
computer operating system, the core
that provides basic services for all other
part of the operating system.
• A kernel can be contrasted with a shell,
shell is the outmost part of an
operating system that interacts with
user commands
13. LINUX Shells
• Bash shell (Bourne again shell)
– Developed for the GNU Project
– The actual standard Linux shell
– Default shell for Red Hat Linux
• Borne shell (sh)
– Original Unix Shell written by Bill Joy at
UC Barkeley
• C shell (csh)
– Added many features such as command
and job control
14. Red Hat Distributions
• Linux distribution are OSs based on the
Linux kernel
• Red Hat Enterprise Linux
– Stable, thoroughly tested software
– Professional support services
• The Fedora Project
– More and newer applications
– Community supported ( no official
Red Hat support)
– For personal systems
15. The Fedora Project
• Red Hat sponsored open source project
• Focused on latest open source
technology
• Rapid four to six month release cycle
• Available as free download from the
Internet
• Red Hat does no provide formal
support
16. Fedora Core and Fedora Extra
• Fedora Core
- The Fedora Core software repository
contained the base packages require
to run Fedora.
• Fedora Extra
- Extra packages were generally
obtained online, and could be
downloaded with yum or other
package management software.
17. Logging into a Linux System
• Two types of login screens:
- Virtual consoles (text-based)
- Graphical logins (called display manager)
• Login using login name and password
• Each user has a home directory for
personal file storage
18. Virtual Console and Graphical Login
• A typical Linux system will run six
virtual consoles and one graphical
login
– Server system often have only virtual
console
– Desktops and workstation typically has
both
• Switch among virtual consoled by
pressing Ctrl + Alt + (F2—F7)
• Access the graphical console by
19. Starting and Terminating Linux System
• Login
– Process of initiating a Linux
Operating System session
• Logout
– Process of terminating a Linux
Operating System session
20. Elements of the X Window System
• The X Window System is Linux’s
graphical subsystem
• Xorg is particular version of the X
Window System used by Red Hat
– Open source implementation of X
• Desktop environments provided by Red
Had:
– GNOME: the default desktop environment
– KDE: an alternate desktop environment
21. Changing Your Password
• Password control access to the system
– Change the password the first time you log
in
– Change the regularly thereafter
– Select a password that is hard to guess
• To change your password from a
terminal:
# passwd username
22. The root User
• The root user
– a special administrative user
account
– Also called the super user
– root has near complete control over
the system
• Do not login as root
