UNIX is a specific type of operating system.. it is multiuser and multitasking operating system...

1. Seminar Presentation
By:- Ajeet Kumar Kushwaha
Computer & Science Engg.
Roll No:-107191004

2. Gbtu Code:-719

3. Contents..
 What is UNIX
 History of UNIX
 Why use UNIX
 UNIX Structure
 Commands
 File Structure
 Applications of UNIX
 Advantages and Disadvantages of UNIX

4. What is UNIX:-
 UNIX once referred to a specific operating system.
 It is available in variety of “flavors” like as BSD, sun
OS, Solaris, etc.
 UNIX operating system is a large program(mostly
coded in C) that turns the computer into a usable
machine.
 It provides a number of facilities:
 Management of hardware resources
 Directory and file system
 Loading/ execution/ suspention of programs

5. Cont…
 UNIX is not a single operating system. It is a family of
operating system.
 It is a multitasking, multi-user computer operating
system.

6. History of Unix:-
 UNIX was first developed in 1969 by a group of AT&T
Bell labs, including Ken thompson, Dennis Ritchie.
 It was first developed in assembly language, and in
1973 it was recoded in C.
 In 1990 LINUX was developed which is a flavor of
UNIX.
 Now UNIX is wide spread and available from many
sources.

7. Why use UNIX:-
 Multi-user operating system
 Multitasking operating system
 Time sharing operating system
 Portability
 Network capability
 Easy to program
 I/O independence
 Communicating among users

8. Unix Structure:-
The operating System
User
programs
Kernel
Hardware
Shell

9. User programs:-
The UNIX System contains several hundred utilities or user
programs. Commands are also known as tools, because they
can be used separately or put together in various ways to carry
out useful tasks.
Kernel:-The kernel is the part of the operating system that
interacts directly with the hardware of a computer, through
device drivers that are built into the kernel. It provides sets of
services that can be used by programs

10. Cont..
Shell:-The shell reads your commands and interprets them as
requests to execute a program , which it then arranges to have
carried out. Because the shell plays this role, it is called a
command interpreter.

11. Command Use
passwd Change your password
date Get the current date and time
cal Display a calendar
who List all users who are currently logged in
finger username Get information about username
write username Send a chat message to username
talk username Open a chat session with username
mesg y
mesg n
Accept or block incoming messages
man command Get information about command
mailx
mailx address
Read e-mail messages, or send an e-mail to address
exit Log out of the system
shutdown poweroff Turn off the machine
COMMANDS:-

12. File structure:-
the UNIX file system is called a hierarchical file system. Within
the UNIX System, there is no limit to the number of files and
directories you can create in a directory that you own. File
systems of this type are often called tree-structured file
systems,

13. Extension File Type Extension File Type
.au Audio .mpg, .mpeg MPEG video
.c C language source code .o Object file (compiled and
assembled code)
.cc C++ source code .pl Perl script
.class Compiled Java file .ps PostScript file
.conf Configuration file .py Python script
.d Directory .sh Bourne shell script
.gif GIF image .tar tar archive
.gz Compressed with gzip .tar.Z, .tar.gz Files that have been archived
with tar and then compressed
.h Header file for a C program .tex Text formatted with Tex/LaTeX
.html Webpage .txt ASCII text
.jar Java archive .uu, .uue Uuencoded file
.java Java source code .wav Wave audio
.jpg, .jpeg JPEG image .z Compressed with pack
.log Log file .Z Compressed with compress

14. Application Of Unix:-
 Applications built using UNIX commands, tools, and programs
 horizontal applications like as government, industry, and
education
 Others are industry-specific and are known as vertical
applications
 web browsers and web server application
 Another important class of applications deals with multimedia.
Such applications let users create and view multimedia files,
including audio, images, and video.

15. Advantages of UNIX:-
 Unix is multitasking and multi-user operating system.
 Access control and security.
 A powerfully unified file system.
 Optimized for program development.
 Available on wide variety of machines.

16. Disadvantages:-
 Software incompatibility
 incompatible disk formats.