Unix Operating System and Its Salient Features

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Developed by AT & T, Bell Laboratories, the UNIX operating system was once used only on mini and mainframe computers, but has now been adapted for microcomputers as well. UNIX is a portable. Multi-user, Multitask, layered operating system. The Kernel interfaces directly with the computer's CPU and is modified to run on the different Cup's and to alter the hardware related operations such as memory management.

Because UNIX is written in C, a high level language, it is less hardware dependent than operating system written in lower level language; this makes UNIX easy to transport from one system to another. Surrounding the Kernel is the "Shell" which serves as a programming language and as a command language interpreter, reading lines typed in by the user and interpreting them as requests to execute certain programs.

The original text oriented UNIX user interfaces is a shell and contains commands that has been criticized as being cryptic and thus difficult to remember. More user friendly GUIs have been developed for use with UNIX by companies such as SUN Microsystems.

Salient Features of Unix:

The UNIX operating system offers many salient features. Some of these important features are discussed below:

Multitasking Capability:

This capability allows the system to perform several tasks simultaneously. For instance, UNIX can print one document, edit another and sort a list of files at the same time. Multiple tasks can be carried out by placing other tasks in the background while you work on one task at a time. The current tasks are said to be in the foreground. Normally the tasks that do not require active interaction from the user are placed in the background; the lower will be the system response.

Multi-User Capability:

Multi-user operational system permits several users to use the same computer to carry out their job. Several terminals are connected to a single powerful computer and each user of the terminal can be a programmer, program access files and prints document at the same time. Need for the multi-user environment arises when several programmers work on developing module of the same software. Multi-user environment ensures complete coordination and compatibility and saves a considerable amount of time by allowing several users on a set of information at a time. Buying single multi-user computer is far more economical and efficient than buying several single users computers.

System Portability:

The UNIX operating system can port itself to another installation without any major changes. This ability to adapt itself to different computers has made UNIX very popular. UNIX runs on the more brands of computers than any other operating system.

Communication:

UNIX supports two major types of communication:

1. Communication between different terminals connected to the same computer.

2. Communication between users of the one computer at the specific location to the users of another type and size of a computer located elsewhere. The two computers may be located in different offices or different countries or continents. These types of communication is achieved by a mail system based on wide area and may be connected through telephone lines or satellite.