Google
 

 

up previous next contents
Up: IntroToUnix Previous: Contents Next: Getting Started   Contents

Introduction

Objective

This section provides an introduction to the UNIX (and Linux) operating system and the UNIX - Level I course material.

Introduction

  1. Introductory Information
  2. Instructor's background
  3. Student's background and needs
    1. DOS experience
    2. UNIX experience
    3. Other computing background
    4. Your UNIX goals

Goals of Unix - Level 1

  1. Teach the Basic UNIX Commands
  2. Supply An Overall Understanding of UNIX Technologies
  3. Plenty of Examples to Work From
  4. Plenty of Hands-On Experience

UNIX - What Is It?

  1. UNIX is an operating system for computers
  2. UNIX is an operating system for computers. An operating system is the software that allows use to use a computer - it is the interface between you and the computer hardware.
  3. There are many other operating systems in the computer world, such as MS-DOS, IBM’s OS/2, Microsoft’s Windows NT, Windows 95/98/2000 and XP, and Digital Equipment Corporation’s VMS operating system.

UNIX is multi-user

Unlike MS-DOS, OS/2, and Windows NT/2000/XP, UNIX is a multi-user operating system. This means that multiple users can log in to a computer at one time, and use the resources of that computer. Resources can be a machine’s CPU, it’s software applications, as well as it’s hard disk drives, printers, modems, etc.

UNIX is portable and scalable

Unlike MS-DOS, OS/2, Windows NT/2000/XP and VMS, UNIX is available on a wide range of hardware platforms, from personal computers to mainframes to the world’s fastest supercomputers.

UNIX is multi-tasking

UNIX is also a multi-tasking operating system. This means that each user can perform multiple tasks simultaneously, such as:

  1. Editing a file
  2. Compiling a software program
  3. Formatting a floppy disk
  4. Printing a document

UNIX systems are Open

Because UNIX systems communicate through industry-standard TCP/IP communication protocols, and use an industry-standard interface based on an X-Windows and Motif graphical environment, and share disk drives through the use of industry-standard NFS technology, they are called "open systems".

Advanced technology is shared between UNIX vendors to create more flexible solutions for clients. UNIX operating systems typically start with source code that is now licensed by Novell, Inc. Novell’s UNIX Systems Group licenses the actual UNIX source code to vendors such as IBM, Hewlett-Packard, Sun Microsystems, SCO (Santa Cruz Operation), and many others. (The UNIX source code was owned by AT&T and UNIX Systems Laboratories until 1994.)

Also, the API's (Application Programming Interface) for these operating systems are published by the software vendors, and are very consistent. It is generally a simple task to port a software application from one vendor's UNIX platform to another. This creates a lot of competition in the UNIX marketplace, which is good for computing customers.

This sharing of technology between UNIX vendors is in stark contrast to other vendors operating systems, which are labeled proprietary.

Other UNIX advantages

UNIX also offers other advantages as an operating system:

  1. It is a programmable operating system. Standard UNIX commands can be combined in an endless variety of ways to achieve different tasks. This offers the user an enormous amount of power and flexibility.
  2. Built-in TCP/IP networking, for communications across all forms of networks, and between all forms of computers. Unlike other vendors, UNIX systems do not force you to use proprietary communication protocols to have computers speak to each other (i.e., open systems).
  3. UNIX systems from different vendors can work together in the same computer environment. They can share disk drives, printers, CPU's, terminals, and other resources.
  4. Industry-Standard X-Windows and Motif Graphical User Interface (GUI) that allow windows to be displayed across a network onto more than one graphics terminal.

Important Concepts Necessary to Understanding UNIX

Hierarchical File System

Starts at "/" (root), branches off from there.

Virtual Memory

Not limited to the physical memory (RAM) installed in the system.

UNIX Shells

  1. "Shells" interpret the commands that you type
  2. sh, csh, ksh
  3. Metacharacters (characters that have special meanings to your shell)

Multi-user

Multiple users can use the CPU of one machine simultaneously.

Multiprocessing

Each user can run multiple tasks simultaneously.

The X-Window System

  1. Device-independent "windowing" system
  2. Industry Standard (X11R5)
  3. Standard across all UNIX platforms
  4. The only true "client-server" windowing system

Acronyms

Most UNIX commands are abbreviations or concatenations of multiple words.