Features Of UNIX

1. Multi User

2. Multi Tasking

3. Open System

4. Programming Facility

5. Security

6. Portability

7. Communication

8. Help Facility

 

1. Multi User : More than one user can access same system resources (hardware,memory,printer,etc..) at the same time known as multi user.

2. Multi Tasking : Execution of more than one task (or) application simultaneously known as multi tasking. The main concept of multi tasking is maximum utilizing CPU resources.

Eg : At a time we can run multiple tasks, i.e editing task,compile task,printing,etc..

3. Open System : UNIX had bright feature, i.e open source code. Any user can modified unix open source code, can develop own O/S based on our business requirements.

It is developed “AT&T” bell labs employes in 1973 by using C-Language.

Using unix open source code

Vendor	Operating System	File System
Redhat	RHEL	ext2,ext3,ext4
SUN-Microsystem	Sun-Solaris	UFS – Unix File System
IBM	IBM-AIX	JFS – Journal File System
HP	HP-UX	HPFS – High Performance FS
SG(Silicon Graphics)	IRIX
SCO(scanta cruz operations)	SCO – UNIX
Microsoft	Xenix

Any Operating System developed based on UNIX open source code known as flavour of Unix

4. Programming Facility : UNIX O/S provides shell, shell works like a programming language. It provides commands and keywords.

         

Scripting Language	Programming Language
i). It is a interpreter based language.	i). Compiler based language.
ii). Interpreter converts high level instructions into machine language line by line.	ii). The whole program in a single short into machine language.
iii). It doesn,t create .exe files.	iii). Create .exe files
iv). No need to compile the program .	iv). Need to compile the program .
v). It takes less time of code.	v). Takes numerous lines of code.
vi). Reduce cost of maintenance .	vi). Increase cost of maintenance .

        

5. Security : UNIX given 2 levels of security 

a) System level security

b). File level security

a) System level security : System level security controlled by System Administrator .

b). File level security : File level security controlled by owner of the file.

6. Portability : portability means independent of hardware and processor. One of the main reasons for the universal popularity of unix is that it can be ported to almost any computer system. It works with 8088 processor to super computer.

7. Communication Facility : The main concept of communication facility exchanging of information (or) files from one user account to another user account.

Unix provides electronic mail. The communication maybe within the network of a single main computer (or) between two or more such computer networks.

The user can easily exchange mail, data, programs through such networks.

8. Help Facility : UNIX provides manual page for Unix commands. Man is the command to see the help.

           Eg :   # man useradd

                    # man userdel

                    # man vim