UNIX was earlier known to be UNICS, which stands for UNiplexed Information Computing System..
UNIX is a popular operating system, first got released in 1969. UNIX is a multi-tasking, powerful, multi-user, a virtual OS which could be implemented on a variety of platforms(Eg. Desktops, Laptops, Servers, and mobile devices, etc).
The development of UNIX system got started at Bell Labs by the scientists, Ken Thompson, Dennis Ritchie and various others. The first version of this operating system was written in assembly language, but later during 1973, Version 4 was written in C language. During the 1990s, the UNIX system started gaining popularity as the Linux distributions were developed by several programmers. In 2000, Apple released its own UNIX system, known as Darwin, which later became MacOS.
The UNIX system basically comprises three components:
- Shell: It acts as an interface between the kernel and the user. The user has to go under the authentication check before entering into the shell.
- Program: It can be said that everything inside UNIX is either a file or a program. A process is a program under execution having unique PID(program Identifier), used to identify it.
- Kernel: The Kernel is responsible for allocating time and memory to programs. It also handles file storage and communication while responding to the system calls.
command option(s) filename(s)
Characteristics of UNIX
- Portability: The UNIX system is written in HLL which makes it easier to understand, modify and transport it to other machines. This feature of UNIX operating system helps the user to change and compile the code on a new machine.
- Multi-tasking: UNIX supports more than one process to run at a time i.e., if a process is running, then other processes can also be run in the background.
- Pipes and Filters: UNIX contains pipes and filters which help in making of complex programs from simpler programs.
- Shell :UNIX has a simple interface which helps the user to perform various functions. The shell hides the intricate hardware details from the user.
- Extensive Library: The UNIX has a support of extensive library which makes it a useful and relevant
Advantages of UNIX
- The main advantage of Unix is its portability which helps the user to run the program on different machines.
- UNIX makes minimum use of physical memory usage while running the various tasks flawlessly.
- UNIX is capable to perform complex tasks with the minimal load and efficiently.
- It supports Hierarchical File system which helps for easy maintenance and efficiency.
- UNIX system is secure due to its strong server validation and authentication.
Disadvantages of UNIX
- UNIX operating system is command line based which increases the difficulty for the casual users to use it. It is meant for expert programmers who know command line commands very well.
- Documentation of various UNIX tools is hard to find.
- The commands used are cryptic, makes use of special characters which makes it difficult for new users to handle.