An Introduction to Red Hat Linux

An Introduction to Red Hat Linux

Course Contents of Red Hat Linux –

1. File and Directory Operations
2. User Information
3. File Permissions
4. Linux File System Essentials
5. X-Window System and GUI application (introduction)
6. Standard I/O Pipes
7. String Processing
8. Process
9. VI editor
10. Bash Shell and Shell Scripting
11. Basic Network Clients

Introduction

An operating system (OS) is software designed to act as an interface between the computer and the user. It performs various important functions such as ,
· An OS is a command interpreter. It translates the high level language to machine language and vice versa.
· An OS acts as process manager. There are various processes running simultaneously in a computer. The amount of time to be spent on a process by the CPU is decided by the OS.
· An OS is a memory manager. As said above, there are various processes running simultaneously in a computer which require memory from CPU. The amount of memory to be allocated on certain process is also decided by the OS.
· An OS acts as a hardware or peripheral manager. The task of accepting input producing the output and redirecting to different peripherals is done by the OS.

About Linux

Linux is one of the popular OS in the market today. It is developed form of UNIX. So, most of its features are UNIX-like. Most of the tools found in UNIX are supported in Linux.

UNIX was designed and developed in 1960s to provide an environment to create programs. It became popular and got spread to educational institutes, research labs and industries. Later a Finnish student Linus Torvalds developed LINUX from UNIX and made the source code available on the internet. Later more developers added additional functions to LINUX.

UNIX principles
· Everything is a file including hardware.
· Configuration data are stored in the text format.
· Small-single purpose programs are present.
· It has ability to chain programs.

Linux has many unique features.
· It has a kernel programming interface. Kernel is responsible for controlling the resource and scheduling user jobs. All the programs interact with the kernel through system calls.
· Linux is a multi-user OS. This allows many users to access all the system resource almost simultaneously.
· It is a multitasking OS. It can run up to 32768 processes at a time.
· Files are arranged under a directory.

Structure of Linux system
Linux system structure consists of Kernel, Shell, Tools and Applications.

User Applications
Hardware
Kernel
Shell and Utilities

Layer view of Linux Operating System

Kernel is the heart of the Linux OS. It is loaded in the memory when computer is booted. It interacts with the hardware. It manages the system resources, allocates time for different users and process, and sets process priorities.
Shell acts as the interface between user and the computer. There are different types of Shell available in Linux. Among them, bash shell is widely used.

Linux has its own applications for word-processing, spreadsheet, creating presentation, image processing etc.