What is unix

What is Unix?

Unix and Unix-like operating systems are a family of computer operating systems that are derived from the original Unix System from Bell Labs.

It provides users with-

             Program Development Tools

             Electronic communication facilities such as e-mail, text editors and text formatters

Unix is the most powerful and popular multi-user and multi-tasking Operating System. The basic concepts of Unix were originated in the Multics project of 1969. The Multics system was intended as a time-sharing system that would allow multiple users to simultaneously access a mainframe computer.

Ken Thompson, Dennis Ritchie, and others developed the basic building blocks of Unix. From there, multiple generations of Unix were developed for various machines.

Growing incompatibility between these systems led to the creation of interoperability standards like POSIX and Single Unix Specification.

Unix programs are designed around some core philosophies that include requirements like single purpose, interoperable, and working with a standardized text interface. Unix systems are built around a core kernel that manages the system and the other processes.

Kernel subsystems may include process management, file management, memory management, network management and others.

Salient Features of Unix

There are several prominent features of Unix, and few among them are stated below:

• It is a multi-user system where the same resources can be shared by different users.

• It provides multi-tasking, wherein each user can execute many processes at the same time.

• It was the first operating system that was written in a high-level language (C Language). This made it easy to port to other machines with minimum adaptations.

• It provides a hierarchical file structure which allows easier access and maintenance of data.

• Unix has built-in networking functions so that different users can easily exchange information.

• Unix functionality can be extended through user programs built on a standard programming interface.

Unix Architecture

We will understand how user commands are executed in Unix. 

Unix operating system has three components

= KERNEL

= SHELL

= FILE SYSTEM

1.  KERNAL

         The kernel is the core of the operating system that directly interacts with the underlying hardware to provide a set of    standard services. It is referred as a boot of the system. It has the complete control everything in the system. 

It is the lowest level of any operating system.

2. SHELL

         User commands are often entered on a command line interface that is provided by a ‘shell’. The shell is a program that reads the user commands, evaluates it, and then prints the result.

3. FILE SYSTEM

It is the central part of operating system. It was also known as the first part of the system. A file is a smallest unit in which information is stored. All files stored in directories. These directories are in a tree like structure and these structure is called as directories.

Proprietary Unix operating systems (and Unix-like variants) run on a wide variety of digital architectures, and are commonly used on web servers, mainframes, and supercomputers. In recent years, smartphones, tablets, and personal computers running versions or variants of Unix have become increasingly popular.