Datasheet

Part 1: Starting Out with Ubuntu

The GNU organization (GNU stands for GNUs Not UNIX) developed a complete set of

UNIX utilities but had no kernel system to run them on. These utilities were developed

under a software philosophy called open-source software (OSS).

The concept of OSS allows programmers to develop software and release it to the world

with no licensing fees attached. Anyone can use the software, modify it, or incorporate

it into his or her own system without having to pay a license fee. Uniting Linus’s Linux

kernel with the GNU operating system utilities created a complete, functional, free oper-

ating system.

The Core GNU Utilities

The GNU project was mainly designed for UNIX system administrators to have a UNIX-

like environment available. This focus resulted in the project porting many common UNIX

system command line utilities. The core bundle of utilities supplied for Linux systems is

called the coreutils package.

The GNU coreutils package consists of three parts:

Utilities for handling ﬁles

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Utilities for manipulating text

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Utilities for managing processes

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These three groups of utilities each contain several utility programs that are invaluable

to the Linux system administrator and programmer.

The Shell

The GNU/Linux shell is a special interactive utility. It provides a way for users to start

programs, manage ﬁles on the ﬁlesystem, and manage processes running on the Linux

system. The core of the shell is the command prompt. The command prompt is the inter-

active part of the shell. It allows you to enter text commands, then it interprets the com-

mands and executes them in the kernel.

The shell contains a set of internal commands that you use to control things such as copy-

ing ﬁles, moving ﬁles, renaming ﬁles, displaying the programs currently running on the

system, and stopping programs running on the system. Besides the internal commands,

the shell also allows you to enter the name of a program at the command prompt. The

shell passes the program name off to the kernel to start it.

There are quite a few Linux shells available to use on a Linux system. Different shells

have different characteristics; some are more useful for creating scripts, and some are

more useful for managing processes. The default shell used in all Linux distributions is

the bash shell.

Although the bundling of the Linux kernel and GNU utilities is often just called

Linux, you will see some Linux purists on the Internet refer to it as the GNU/

Linux system to give credit to the GNU organization for its contributions to the

cause.

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