LINUX

WHAT IS LINUX ?

Free

Linux in a Unix-like computer operating system.

Linux is a very popular open source operating system.

Linux is the software on a computer that enables applications and the

computer operater to access the devices on the computer to perform

desired functions.

HISTORY OF LINUXThe unix operating system was implemented in 1969, by ken Thompson ,Dennis Ritchi,

Douglas Mcllroy and Joe Ossanna.

In Sept 1991, Linus Torvalds, a second year student of Computer

Science at the University of Helsinki, developed the preliminary

kernel of Linux, known as Linux version 0.0.1

Ken Thompson and Dennis RitchieLinus Torvalds

Linux is Virus Free!!Linux is "virus-free" in that there are essentially no viruses for Linux in the wild, although research viruses certainly do exi

WHY LINUX IS VIRES FREE?

Most of the viruses are in the for of executable files Thus the viruses will be able to execute and run instructions only in

WHAT IS KERNEL?Kernel is used in UNIX like systems and is considered to be the heart of the operating system. It is responsible for communic

TYPE OF KERNELMICROKERNEL(takes the approach of only managing cpu, memory &ipc).

MONOLITHIC KERNEL(opposite to microkernel).

HYBRID KERNEL(have ability to pick superviser mode &user mode).

KERNEL ACTIVITIESThe Kernel task manager allows tasks to run concurrently.

Managing the computer resources.

Kernel is responsible for Process management.

Responds to system calls.

WHAT IS LINUX SHELL ?

Linux shell is a user interface used for executing the commands.Shell is a program the user uses for executing the commands. In UNIX

TYPES OF LINUX SHELLS

Bourne Shell(Steve Bourne).

C Shell(Bill Joy).

TC Shell.

Korn Shell(David Korn).

Bourne-Again Shell(Brian Fox and Chet Ramey).

Linux Command Basics

To execute a command, type its name and arguments at the command line

ls -l /etc

Command nameOptions(flags)

Arguments

DEADLY COMMANDS IN LINUX

rm -rf / – Deletes Everything!

:(){ :|: & };: – Fork Bomb

mkfs.ext4 /dev/sda1 – Formats a Hard Drive

command > /dev/sda – Writes Directly to a Hard Drive

dd if=/dev/random of=/dev/sda – Writes Junk Onto a

mv ~ /dev/null – Moves Your Home Directory to a Black

ADVANTAGES OF LINUX

COST.

LINUX IS EASY TO INSTALL!.

LINUX IS VERY STABLE.

SECURITY.

CHOICE(Freedom).

SOFTWARE.

HARDWARE.

LINUX TYPICALLY DOES NOT SLOW DOWN OVER TIME!.

DISADVANTAGES OF LINUX

UNDERSTANDING.

MANY WINDOWS PROGRAMS WILL NOT RUN IN LINUX..

ALTERNATIVE PROGRAMS.

MORE TECHNICAL ABILITY NEEDED.

THANK YOU