CHAPTER ONE
1.0 INTRODUCTION TO OPERATING SYSTEM
Programs to access system resources (e.g. the CPU, memory, disk, moderns, printer network an operating system (OS) is a resource manager. It take the form of a set of software routine that allow users and application cards etc.) In a safe, efficient and abstract way.
For example, an OS ensure safe access to a printer by allowing only one application program to send data directly to the printer at any one time. An OS encourage efficient use of the CPU by suspending programs that are waiting for I/O operations to complete to make way for program that can use the CPU more productively. An OS also provides convenient abstractions (such as file rather than disk locations) which isolate application programmers and users from the details of the underlying hardware.
Operating system manage overall activities of a computer and the input and output device attached to the computer. It is the first software you see when you turn on the computer, it is the software that enable all program you use. At the simplest level, an operating system does two things.
The first, it manage the hardware and the software resources of the computer system. These resource include the processor, memory, disk space etc.
The second, it provide a stable consistence way for application to deal with hardware without having to know all the details of the hardware.
1.1 INTRODUCTION TO LINUX OPERATING SYSTEM
Linux was originally developed as a free operating system for personal computer based on the Intel x86 architecture, but has since been ported to more computer hardware platform than any other operating system.
Thanks to its dominance on smartphone, android, which is built on top of the Linux kernel, has the largest installed base of all general-purpose operating system. Linux, in its original form, is also the leading operating system on servers and other big iron system such as mainframe computer and virtually all fastest supercomputers, bus is used on only around 1.6% of desktop computer with Linux-based Chrome OS taking about 5% of the overall and nearly 20% of the sub-$300 notebook sales. Linux also run on embedded systems, which are device whose operating system is typically built into the firmware and is highly tailored to the system; this include the smartphones and tablet computer running Android and other Linux derivatives, Tivo and similar DVR device, network routers, facility automation controls, televisions, video game consoles, and smart watches.
The development of Linux is one of the most prominent example of free and open-source software collaboration. The underlying source code may be used, modified and distributed commercially or non-commercially by anyone under the term of its respective licenses, such as the GNU General Public License, Typically, Linux is package in a form known as a Linux distribution, for both desktop and server use. Some of the popular mainstream Linux distribution are Debian, Ubuntu, Linux Mint, Fedora, open SUSE, Arch Linux and Gentoo, together with commercial Red Hat Enterprise Linux and SUSE Linux Enterprise Server distributions. Linux distribution include the Linux kernel, supporting utilities and libraries, and usually a large amount of application software to fulfill the distribution’s intended use.
Distribution oriented toward desktop use typically include a windowing system, such as X11, Mir or a way land implementation, and an accompanying desktop environment, such as GNOME or the KDE software compilation; some distribution may also include a less resource- intensive desktop, such as LXDE or Xfce. Distribution intended to run on servers may omit all graphical environments from the standard install, and instead include other software to set up and operate a solution stack such as LAMP. Because Linux is freely redistributable, anyone may create distribution for any instead use.
1.1.0 FEATUURES OF LINUX OPERATING SYSTEM
Linux has several silence feature, some of the importance ones are:
Multiuser capability: This is a capability of Linux OS where, the same computer resource – hard disk, memory, etc. are accessible to multiple users. Of course, not on a single terminal, they are given different terminals to operate from. A terminal will consist of at least a monitor/VDU, keyboard and mouse as input device. All the terminals are then connected to the main Linux sever or Host Machine, whose resource and connected peripheral device such as printer, can used.
Client /server Architecture is an example of multiuser capability of Linux, where different clients are connected to a Linux server. The client sends request to the server with a particular data and server request with the processed data or the file requested, client terminals is also known as Dumb Terminals.
