The Red Hat Linux Distribution Computer Science

Essay add: 11-01-2017, 20:19   /   Views: 22

Red Hat Linux is a distribution which includes the basic Linux operating system with a number of free applications. These include a fully featured office suite as well as graphics and multimedia programs that can satisfy most users. Comparable Microsoft programs cost many hundreds of dollars for each computer.

Linux is fast becoming the major alternative to Microsoft windows. As a server, it includes all the tools that might be needed to configure and administer a wide variety of networks.

BASIC COMPONENTS OF LINUX

Linux can be broken down into a number of modules. The modular nature of Linux allows developers to work independently and more efficiently. The six categories of modules associated with Linux are kernel, network, init, daemons, shells, utilities, XWindows.

KERNEL

The kernel is the most important part of any Operating System. It allows Linux and any software that you install to communicate with the computer hardware. It does this through dedicated device drivers.

NETWORK

Linux computers are most commonly organized in a client/server network. Some computers act as work stations or clients for users; others are servers, which control resources shared by multiple users on different workstations.

INIT

When Linux is booted on the computer, the kernel loads and starts init. The init program then mounts your drivers, and starts your terminal program, known as mingetty. When logging in the terminal program starts command line interface shell. After Linux boots the computer, init watches for anything that might shut down the computer such as power failure etc.

DAEMONS

A Daemon is a computer program that runs in the background, rather then under the direct control of a user, they are usually initiated as background processes.

SHELLS

Shell is a user program or it's environment provided for user interaction. Shell is an command language interpreter that executes commands read from the standard input device (keyboard) or from a file. Shell is not a part of system kernel, but uses the system kernel to execute programs, create files etc.

UTILITIES

From a certain point of view, Linux can be seen primarily as a set of utilities bonded together by a common kernel. These utilities form the "toolkit" model that has endeared Unix to programmers, system administrators, and advanced users for over three decades. It is frequently the utilities that attract new users to Unix in the first place.

Linux utilities come in two basic flavors: open source and commercial. Some commercial products, such as RealPlayer, are available for free, while others, such as the BRU tape backup software, are available for a fee. The majority of Linux utilities are free, open-source packages.

X WINDOWS

The X-Window-System is a computer software system and network protocol that provides a graphical user interface (GUI) for networked computers, and was initially developed as part of Project Athena. It implements the X display protocol  and provides  windowing  on  raster graphics (bitmap) computer displays and manages keyboard and pointing device control functions. In its standard distribution, it is a complete, albeit simple, display and human interface solution, but also delivers a standard toolkit and protocol stack for building graphical user interfaces on most Unix-like operating systems and OpenVMS, and has been ported to many other contemporary general purpose operating systems. Desktop environments of Unix-like operating systems offer the X Window System.

-----------------------------------------------------------------------------------------------SOLARIS OPERATING SYSTEM

Solaris is a UNIX based Operating System introduced by Sun Microsystems, a subsidiary of Oracle Corporation, in 1992 as the successor to SunOS.

Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace and ZFS. Solaris supports SPARC-based and x86-based workstations and servers from Sun and other vendors, with efforts underway to port to additional platforms.

FEATURES OF SOLARISSOLARIS SOURCE COMPATIBILITY

The Solaris OS is built from a single source base and features the same programming interfaces on any supported platforms. This means that applications developed for SPARC systems can be easily recompiled for x86 systems and vice versa.

PREDICTIVE SELF HEALING

The Solaris Operating System introduces a new architecture for building and deploying systems and services capable of Predictive Self-Healing. This feature has advanced backgrounds error detection, correction and recovery, which proactively offlines components before system failure.

SOLARIS ZFS

The Solaris ZFS file system is designed from the ground up to meet the emerging needs of a general purpose file system that spans the desktop to the data centre. ZFS is a highly scalable and provides excellent performance with end to end data integrity.

SOLARIS DTRACE

Designed to be more powerful than any diagnostic tool, DTrace is an excellent dynamic tracing framework for troubleshooting your network and turning system performance in real time. DTrace lets you see your entire system in a way that reveals systematic problems that were previously invisible and fixing performance issues that used to go unresolved.

ADVANCED SECURITY

The Solaris OS is designed to provide comprehensive, in-depth security, helping to protect the enterprise at multiple levels. Specific features include Solaris containers technology for application isolation, secure by default for system network hardening. Solaris Process rights Management, and an encryption infrastructure that makes it easy for applications to take advantages of high-grade cryptographic algorithms and acceleration hardware.

-----------------------------------------------------------------------------------------------MAC OS X

Mac OS X is a uniquely powerful development platform, bringing a 32-bit and 64-bit architecture and multiprocessor capability to the desktop and server arenas. It provides an extremely productive high-level programming environment, Cocoa, combined with the full power of real UNIX®, as well as a host of open source web, scripting, database, and development technologies.

FEATURES AND THEIR USAGE:

Mac OS X includes a number of easy-to-use technologies that play a dual role as great applications and system services, allowing developers to enhance their applications with iChat Theater, Time Machine, Spotlight, Dashboard, Automator, and VoiceOver.

iCHAT THEATER

iChat Theater takes instant messaging far beyond simple text-into the world of multimedia, allowing you to to share audio and video. As a developer, you too can access these features and create applications that intelligently determine who is online, share video, and control iChat through AppleScript.

TIME MACHINE

Time Machine is the new file backup and recovery technology on Mac OS X. As a developer, you can take advantage of Time Machine to set the backup policy for files created by your application.

SPOTLIGHT

Spotlight is an advanced search technology that is tightly integrated with the file system, ensuring that a file is properly indexed with every access. You can use Spotlight queries from within your application, and if your application uses unique file types, you can provide a Spotlight plug-in that handle your files.

DASHBOARD

Dashboard brings to Mac OS X a unique class of mini-applications called Widgets, which are perfect for working with small amounts of data or interacting with other applications, both on your desktop and across the web. Widgets can easily be created using Dashcode and WebClip, which are bundled into Mac OS X. Or your can roll your own using a mixture of HTML, javascript, and CSS.

AUTOMATOR

Automator helps you streamline repetitive everyday manual tasks quickly, efficiently, and easily without programming.

VOICEOVER

Mac OS X also includes VoiceOver, the spoken interface designed for those with visual and learning disabilities. For developers, the Accessibility API in Mac OS X helps you build applications that are accessible to assistive technologies, so you can bring your application to as broad an audience as possible.

ARCHITECTURE

Mac OS X provides outstanding stability and performance. It starts with a 64-bit, open source UNIX core. Apple integrated the widely-used FreeBSD 5 UNIX distribution with the Mach 3.0 microkernel to deliver key functionality and a solid foundation. Preemptive multitasking, symmetric multiprocessing (SMP), and protected memory form the cornerstones of this foundation.

GRAPHICS INTERFACE

Mac OS X is built around a powerful, integrated stack of graphics technologies, including OpenGL, Core Animation, and Core Image. These provide a solid foundation for application developers to create great applications. Mac OS X's multithreaded graphics layer handles application windowing, 2D and 3D drawing, animation, and multimedia. Together, the subsystems of the graphics layer provide fast, elegant graphics to the operating system and to your application, making possible cutting-edge user interface features.

RUNTIME FLEXIBILITY

Mac OS X provides several runtime environments, all of which integrate under a single desktop environment. Whether you prefer an object-oriented application framework, procedural APIs, a highly-optimized and tightly integrated implementation of Java SE, BSD UNIX APIs and libraries, or X11, you can run it all on the Mac OS X desktop.

DEVELOPMENT TOOLS

Mac OS X provides you with a full suite of free developer tools to prototype, compile, debug, analyze, and optimize your applications, speeding up your development cycle. Xcode 3 includes a robust Integrated Development Environment (IDE) for writing applications, libraries, and drivers, and a complete set of developer documentation. Underlying Xcode is GCC 4, an Apple-optimized version of the popular open source compiler, plus the GNU Debugger (GDB). Xcode also includes Interface Builder, an easy-to-use graphical editor for designing and managing your application's user interface. Whether you code in Objective-C, C/C++, or another popular language, Xcode can handle it.

-----------------------------------------------------------------------------------------------SYMBION OPERATING SYSTEM

Symbian OS is an operating system designed for mobile devices and smartphones, with associated libraries, user interface, frameworks and reference implementations of common tools, originally developed by Symbian Ltd. It was a descendant of Psion's EPOC and runs exclusively on ARM processors, although an unreleased x86 port existed.

Symbian features pre-emptive multitasking and memory protection, like other operating systems (especially those created for use on desktop computers). EPOC's approach to multitasking was inspired by VMS and is based on asynchronous server-based events

Symbian uses a microkernel, has a request and callback approach to services, and maintains separation between user interface and engine. The OS is optimized for low power battery-based devices and for ROM-based systems ( e.g features like XIP and re-entrancy in shared libraries). Applications, and the OS itself, follow an object-oriented design: model view controller(MVC).

Symbian platform is the open source operating system and software platform for mobile devices created by merging and integrating software assets contributed by Nokia, Sony Ericsson and Symbian Ltd. (through the Symbian Foundation), including the Symbian OS assets as its core. It is being actively developed by the Symbian Foundation.

Symbian OS has made considerable improvements in security. Symbian OS was subject to a variety of viruses, the best known of which is Cabir. Usually these viruses were transferred through Bluetooth communication between the mobile phones. But so far, none have taken any advantage of any flaws in Symbian OS - instead, they have all asked the user whether they would like to install the software, with somewhat prominent warnings that it cant be trusted.

DEVELOPMENT ON SYMBIAN OPERATING SYSTEM

The native language of Symbian is C++, although it is not a standard implementation. There were multiple platforms based upon Symbian OS that provided SDKs for application developers wishing to target Symbian OS devices.

Symbian devices can also be programmed using Python, Java ME, Flash Lite, Ruby, .NET, Web Runtime(WRT) Widgets and Standard C/C++.

----------------------------------------------------------------------------------------------MICROSOFT WINDOWS 98

In nearly 25 years since its initial release in the fall of 1985, Microsoft Windows has established itself as the industry standard graphical environment for personal computers built around Intel microprocessors. Since then several versions of Windows have been released, the latest being Windows 7 released in 2009. But overhere windows 98 will be discussed since major changes took place in windows 98 from its predecessor Windows 95.

After Windows 95 microsoft released Windows 98 and added several new enhancements to this version. The significant in Window's 98 enhancement is the active desktop which merges internet connectivity with the windows 98 desktop. Also Windows 98 includes several features to improve reliability and increase performance.

Windows 98 was the first operating system to use the Windows Driver Model (WDM). This fact was not well published when Windows 98 was released and most hardware producers continued to develop drivers for the older driver standard, VxD. The WDM standard spread years after its release, mostly through Windows 2000 and Windows XP, because these systems are not compatible with the older VxD standard. Today, even if hardware producers are not developing drivers optimized for Windows 98, the drivers written to WDM standards are compatible with Windows 98 based systems.

WINDOWS 98 SYSTEM TOOLSScanDisk 

System utility used to maintain the file system. It offers a DOS and a GUI version. Used to check the integrity of the file system and files stored within.

Disk Defragmenter 

Used to counter the negative effects of filesystem fragmentation. It collects fragmented file parts, reconnects them and rearranges all files in optimal order, thus speeding up file access and allowing faster boot times.

Scanreg

Used to restore the System registry. It tests the registry's integrity and saves a backup copy each time. The maximum amount of copies could be customized by the user through "scanreg.ini" file. Due to a bug the oldest registry copy available cannot be restored (before restoration, the current configuration is backed up and it erases the oldest registry backup listed). The restoration of a faulty registry can only be done in DOS mode. Important DOS commands: scanreg/opt - optimizes the registry by deleting dead entries; scanreg/fix - repairs registry settings.

Msconfig 

A system utility used to disable programs and services which are not required to run the computer. It is a very powerful tool that can greatly enhance the system's stability and speed, but is also capable of rendering the system non-functional if used incorrectly.

Regedit

Allows manual editing of the registry.

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SOURCES

Wikipedia (internet).

Apple Site (internet).

Beginning Red Hat Linux 9 (book)

And Several other sites with little content.

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