2. 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.
3. HISTORY OF LINUX
The 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 Ritchie
Linus Torvalds
5. WHY LINUX IS VIRES FREE?
Most of the viruses are in the for of executable files Thus the viruses will be able to execute an
6. WHAT IS KERNEL?
Kernel is used in UNIX like systems and is considered to be the heart of the operating system
7. TYPE OF KERNEL
MICROKERNEL(takes the approach of only managing cpu, memory &ipc).
MONOLITHIC KERNEL(opposite to microkernel).
HYBRID KERNEL(have ability to pick superviser mode &user mode).
8. KERNEL ACTIVITIES
The Kernel task manager allows tasks to run concurrently.
Managing the computer resources.
Kernel is responsible for Process management.
Responds to system calls.
9. 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
10. 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).
11. Linux Command Basics
To execute a command, type its name and argumen
ls -l /etc
Command name Arguments
Options
(flags)
12. 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
13. ADVANTAGES OF LINUX
COST.
LINUX IS EASY TO INSTALL!.
LINUX IS VERY STABLE.
SECURITY.
CHOICE(Freedom).
SOFTWARE.
HARDWARE.
LINUX TYPICALLY DOES NOT SLOW DOWN