WHAT IS LINUX

INTRODUCTION

Linux is the operating system that is open source and free (free) under the GNU (GNU is not Unix) GPL (General Public License) (YB Mulyana, 2002:1). Open Source meaning of the word is on the Linux source code is included in the core so that the program can be viewed by anyone without having to sign a special agreement. Meaning of the word free is free refers to freedom does not mean free of charge. Linux is free to didupikasikan, modified and distributed for non-commercial purposes and commercial purposes.

HISTORY OF LINUX

Linux was born in 1991. At that time, Linus Torvald, a student from Suoen Tasavalta, the Republic of Finland started the project a stable operating system and can run on Intel x86 machines. Linus Torvald initially using unix-based operating system that is minix. But he felt this operating system has many faults, he was able to make the operating system that is better than minix.In October 1991, Linus Torvald publish operating system called Linux (Linus' Unix). He invites software developers around the world to join together to develop linux operating system. Open Source Era began to show its power.

KERNEL

The kernel is the core or can be regarded as a main engine operating system (YB Mulyana, 2002:2.) In contrast to other operating systems are generally hidden kernel, Linux kernel forward. When talking about linux, then we talk about the linux kernel. Until now, copyright kernel linux-makers still hold the first of Linus Torvald.

Kernel software also is a (set of programs) that make up the system and has a duty to serve a variety of application programs to access the computer hardware in a safe and controlled. Because of limited access to hardware, while more than one program that should be served at the same time, the kernel is also a duty to arrange for when and how long a program can use one part of the hardware. This is called a multiplex.

Access to the hardware directly is a complex problem, therefore the kernel usually implements a set of abstraction (general description) hardware. Such abstractions are a way to hide the complexity, and allows access to the hardware to be easily and uniformly. Thus abstraction (general description) and eventually facilitate the work of programmers.

To run a computer we do not have to use the operating system kernel. A program can be directly loaded and run on a computer machine, ie if the programmer wants to do his job without the help of hardware abstraction or operating system assistance. This technique is used in the early generation computers, so if we want to move from one program to another program, we have to reset and load again these programs.

There are 4 categories of the kernel:
Monolitich kernel

Kernel that provides the hardware abstraction rich and powerful.

Microkernel

Kernel that provides only a small set of simple hardware abstraction, and use the applications referred to as a server to provide other functions.

Hybrid (modification of the microkernel)

Microkernel-like kernel, but it also includes some extra code in the kernel so that it becomes faster

Exokernel

Kernel does not provide hardware abstraction at all, but it provides a set of libraries that provide functions to access hardware directly or nearly directly.

Distro

In the world known by the term linux distribution or in Indonesia called a distribution, or by lovers called linux distributions. "Distro is a linux kernel package plus a collection of GNU software packages and others, which were merged into one, with the aim to simplify the software distribution process". (Ahmad Sofyan, 2006:5).

General 2.5 A Few Things in Linux
There are a few things to know about Linux

1. Linux naming of the files that hold sensitive to uppercase and lowercase letters (case sessitive). Example: linux, Linux, Linux is considered different.
2. Long file names can be up to 256 characters. Characters used for file names are: AZ, az, 0-9, minus sign (-), underscore (_), dot (.). in Linux file names can have whatever the comma, such as-tar.gz linux.13_09_86.
3. Linux considers all the equipment as a file. Example: in Linux there is no disk drive disk drive A or B, but instead use the file / dev/fd0 and / dev/fd1. Similarly with other equipment.
4. There are two types of users, ie root and regular user.
5. Root user is the user who has the highest aksees rights. This user is created automatically during the installation process Linux progress. Root user can do anything, including regulating and controlling the normal user. Regular user is a user who has limited access rights.
6. In text mode, there are two types of signs prompt, namely:

• Sign # indicates the current user is the user root or superuser.
• Sign $ indicates that the current user is a regular user.