Linux

LINUX Overview

• Chapters 1-3 cover foundational concepts of Linux and its operating principles.

OPERATING SYSTEM

• An Operating System (OS) is crucial software that manages hardware and software resources on a computer.

KERNEL

• The OS kernel is:

  • A core software component that manages low-level system features.

  • Responsible for interfacing hardware devices.

  • Allocates memory and CPU resources to programs.

  • Facilitates program interaction.

• Kernels vary between operating systems:

  • Linux kernel differs from MAC OS X and Windows kernels.

  • Each OS is architecturally designed from its kernel upwards.

  • Linux specifically refers to its kernel.

IDENTIFYING AN OS

• Key components of an OS include:

  • Terminal/Shell: Command line interface for user commands (BASH in Linux).

  • Graphical User Interface (GUI): Visual interface with icons and menus.

  • Utility Programs: Tools for various tasks (calculators, text editors).

  • Libraries: Collections of programming functions (libc in Linux).

  • Productivity Programs: Applications like web browsers and word processors.

TERMINAL/SHELL

• Linux command line prompt is called Terminal/BASH.

• BASH stands for Bourne Again Shell.

• Commands differ significantly from Windows.

GRAPHICAL USER INTERFACE (GUI)

• Includes elements such as icons and mouse pointers.

• Common Linux desktop environments:

  • GNOME,

  • KDE,

  • Xfce,

  • Unity.

• GUI features include:

  • Program launchers,

  • File managers,

  • Window controls,

  • Multi-screen support.

LINUX VS UNIX

• Linux is modeled after Unix but is not a Unix OS.

• Linux can run the same software as Unix but may offer more options due to hardware support.

LINUX VS MAC OS

• MAC OS X is a Unix-based commercial operating system.

• Has its unique interface (Cocoa/Aqua).

• Compatibility issues exist between MAC OS X and Linux applications.

• Installation restrictions on non-Apple hardware due to licensing.

LINUX VS WINDOWS

• Key differences include:

  • Licensing: Open-source Linux vs. proprietary Windows.

  • Cost: Linux is often free while Windows is paid.

  • Hardware Compatibility: Windows has broader support from manufacturers for drivers.

  • Software Compatibility: Limited native options for proprietary Windows software like Microsoft Office.

  • Configurability: Linux is highly customizable due to its open-source nature.

  • Security: Linux is less susceptible to viruses; threats usually stem from configuration errors and untrustworthy local users.

DISTRIBUTIONS

• Linux encompasses many distributions, each comprising a Linux kernel and various utilities.

• Differences among distributions can be substantial, impacting user experience and administration.

• Distribution release cycles vary; some follow scheduled updates, unlike Windows.

SOFTWARE LICENSING

• Differentiates between free and open-source software:

  • Free Software: Emphasizes freedom rather than cost (FSF 4 freedoms).

  • Open Source: Collaborative development method prioritizing transparency.

• Not all open-source software is free.

LINUX'S PRINCIPLES AND PHILOSOPHY

• Discusses principles guiding Linux development and community values.

EMBEDDED COMPUTERS

• Linux can be found in diverse applications, including:

  • Smart e-books,

  • DVRs,

  • Smart devices,

  • Appliances.

DESKTOP AND LAPTOP COMPUTERS

• Linux's initial purpose was as a desktop OS; it supports numerous applications:

  • X Window System GUI,

  • Desktop environments like GNOME, KDE,

  • Common applications include Mozilla Firefox (browser), Thunderbird (email), GIMP (graphics), and office suites like Apache OpenOffice.

• Many distributions pre-install these tools.

SERVER COMPUTERS

• Linux is extensively used in server environments:

  • Types of servers include web, email, database, file, and print servers.

• Servers may have minimal GUI requirements to conserve resources; Linux can operate efficiently without a desktop environment.