 |
| Unix Architecture |
Unix Architecture
The architecture of Unix operating system is divided by into four layers. These are the hardware, kernel, system call interface(shell), and application programs/ libraries. The following Unix architecture diagram is showing all the layers.
 |
| Unix Architecture |
The Kernel
The kernel is a part of the operating system. It interacts directly with the hardware of the computer through a device that is built into the kernel.
The main functions of the kernel are,
- Memory management
- Controlling access to the computer.
- Maintaining the file system.
- Handling interrupts.
- Handling errors.
- Performing input and output services.
- Allocate the resources of the computer among users.
The Shell
It is a software program and it acts as a mediator between the kernel and the user. It reads the commands and then interpret them and sends a request to execute a program. So, the shell is also called a command interpreter.
It contains nearly 100 system calls. System calls tell the kernel to carry out various tasks for the program, such as
- Opening a file.
- Writing a file.
- Obtaining information about a file.
- Executing programs.
- Terminating a process.
- Changing the priority of processes.
- Getting the time and date.
Hardware
The hardware includes all the parts of a computer including clocks, timers, devices, parts etc. in the Unix OS Architecture.
Unix Commands and Libraries
This layer of Unix architecture includes user-written applications, using shell programming languages, and libraries of UNIX.
I hope you have cleared about the architecture of UNIX operating system notes.
