ptg ptg Praise for Previous Editions of A Practical Guide to Ubuntu Linux “I am so impressed by how Mark Sobell can approach a complex topic in such an understandable manner. His command examples are espe- cially useful in providing a novice (or even an advanced) administrator with a cookbook on how to accomplish real-world tasks on Linux. He is truly an inspired technical writer!” —George Vish II Senior Education Consultant Hewlett-Packard Company “Overall, I think it’s a great, comprehensive Ubuntu book that’ll be a valuable resource for people of all technical levels.” —John Dong Ubuntu Forum Council Member Backports Team Leader “The JumpStart sections really offer a quick way to get things up and running, allowing you to dig into the details of the book later.” —Scott Mann Aztek Networks “This entire book is a real boon to any neophyte who does not have a solid handle on getting their own answers. That group is the one that I think will benefit the most from A Practical Guide to Ubuntu Linux ® . Random access is easy, but reading cover to cover would also give one a nice foundational understanding of getting the most out of their machine and even enough guidance to get their feet wet in the sysadmin world. Anyone thrown into owning an Ubuntu server may find this to be a handy lifeline.” —JR Peck Editor GeekBook.org “Very well thought out and simplified. [I] would buy another book from this author (Mark Sobell).” —Greg Dye Electronic Tech ® ptg “Ubuntu is gaining popularity at the rate alcohol did during Prohibition, and it’s great to see a well-known author write a book on the latest and greatest version. Not only does it contain Ubuntu-specific information, but it also touches on general computer-related topics, which will help the average computer user to better understand what’s going on in the background. Great work, Mark!” —Daniel R. Arfsten Pro/ENGINEER Drafter/Designer “I would so love to be able to use this book to teach a class about not just Ubuntu or Linux but about computers in general. It is thorough and well written with good illustrations that explain important con- cepts for computer usage.” —Nathan Eckenrode New York Local Community Team “I read a lot of Linux technical information every day, but I’m rarely impressed by tech books. I usually prefer online information sources instead. Mark Sobell’s books are a notable exception. They’re clearly written, technically accurate, comprehensive, and actually enjoyable to read.” —Matthew Miller Senior Systems Analyst/Administrator BU Linux Project Boston University Office of Information Technology “Overall, A Practical Guide to Ubuntu Linux ® by Mark G. Sobell pro- vides all of the information a beginner to intermediate user of Linux would need to be productive. The inclusion of the Live DVD of the Gutsy Gibbon release of Ubuntu makes it easy for the user to test-drive Linux without affecting his installed OS. I have no doubts that you will consider this book money well spent.” —Ray Lodato Slashdot contributor www.slashdot.org “This is well-written, clear, comprehensive information for the Linux user of any type, whether trying Ubuntu on for the first time and want- ing to know a little about it, or using the book as a very good reference when doing something more complicated like setting up a server. This ptg book’s value goes well beyond its purchase price and it’ll make a great addition to the Linux section of your bookshelf.” —Linc Fessenden Host of The LinuxLink TechShow tllts.org “The author has done a very good job at clarifying such a detail-oriented operating system. I have extensive UNIX and Windows experience and this text does an excellent job at bridging the gaps between Linux, Windows, and UNIX. I highly recommend this book to both ‘newbs’ and experienced users. Great job!” —Mark Polczynski Information Technology Consultant “When I first started working with Linux just a short 10 years or so ago, it was a little more difficult than now to get going. . . . Now, someone new to the community has a vast array of resources available on the web, or if they are inclined to begin with Ubuntu, they can literally find almost every single thing they will need in the single volume of Mark Sobell’s A Practical Guide to Ubuntu Linux ® . “I’m sure this sounds a bit like hyperbole. Everything a person would need to know? Obviously not everything, but this book, weighing in at just under 1200 pages, covers so much so thoroughly that there won’t be much left out. From install to admin, networking, security, shell scripting, package management, and a host of other topics, it is all there. GUI and command line tools are covered. There is not really any wasted space or fluff, just a huge amount of information. There are screen shots when appropriate but they do not take up an inordinate amount of space. This book is information-dense.” —JR Peck Editor GeekBook.org “Mark G. Sobell’s freshly revised reference work on Ubuntu Linux may be the most impressive computer book I’ve seen in the last 10 years. If you are currently stranded with a pile of abandoned computers on a desert isle, I’m telling you, this is the book.” —From a review at DesktopLinux.com http://www.desktoplinux.com/ news/NS8801274918.html ptg Praise for Other Books by Mark G. Sobell “I currently own one of your books, A Practical Guide to Linux ® . I believe this book is one of the most comprehensive and, as the title says, practical guides to Linux I have ever read. I consider myself a novice and I come back to this book over and over again.” —Albert J. Nguyen “Thank you for writing a book to help me get away from Windows XP and to never touch Windows Vista. The book is great; I am learning a lot of new concepts and commands. Linux is definitely getting easier to use.” —James Moritz “I have been wanting to make the jump to Linux but did not have the guts to do so—until I saw your familiarly titled A Practical Guide to Red Hat ® Linux ® at the bookstore. I picked up a copy and am eagerly looking forward to regaining my freedom.” —Carmine Stoffo Machine and Process Designer to pharmaceutical industry “I am currently reading A Practical Guide to Red Hat ® Linux ® and am finally understanding the true power of the command line. I am new to Linux and your book is a treasure.” —Juan Gonzalez From the Library of WoweBook.Com ptg A Practical Guide to Ubuntu Linux THIRD EDITION ® From the Library of WoweBook.Com ptg This page intentionally left blank From the Library of WoweBook.Com ptg A Practical Guide to Ubuntu Linux THIRD EDITION Mark G. Sobell Upper Saddle River, NJ • Boston • Indianapolis • San Francisco New York • Toronto • Montreal • London • Munich • Paris • Madrid Capetown • Sydney • Tokyo • Singapore • Mexico City ® From the Library of WoweBook.Com ptg Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed with initial capital letters or in all capitals. Ubuntu ® is a trademark of Canonical Ltd and is used under license from Canonical Ltd. Points of view or opinions in this publication do not necessarily represent the policies or positions of Canonical Ltd or imply affiliation with Ubuntu, www.ubuntu.com. The author and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein. The publisher offers excellent discounts on this book when ordered in quantity for bulk purchases or special sales, which may include electronic versions and/or custom covers and content particular to your business, training goals, marketing focus, and branding interests. For more information, please contact: U.S. Corporate and Government Sales (800) 382-3419 corpsales@pearsontechgroup.com For sales outside the United States, please contact: International Sales international@pearsoned.com Visit us on the Web: informit.com/ph Library of Congress Cataloging-in-Publication Data Sobell, Mark G. A practical guide to Ubuntu Linux / Mark G. Sobell.—3rd ed. p. cm. Includes index. ISBN 978-0-13-254248-7 (pbk. : alk. paper) 1. Ubuntu (Electronic resource) 2. Linux. 3. Operating systems (Computers) I. Title. QA76.76.O63S59497 2010 005.4'32—dc22 2010024353 Copyright © 2011 Mark G. Sobell All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, write to: Pearson Education, Inc. Rights and Contracts Department 501 Boylston Street, Suite 900 Boston, MA 02116 Fax: (617) 671-3447 ISBN-13: 978-0-13-254248-7 ISBN-10: 0-13-254248-X Printed in the United States of America on recycled paper at Edwards Brothers in Ann Arbor, Michigan. First printing, August 2010 From the Library of WoweBook.Com ptg For my sons, Zach, Sam, and Max, each of whom is blooming and bringing light into the world. From the Library of WoweBook.Com [...]... Descriptors 987 Parameters and Variables 990 Array Variables 990 Locality of Variables 992 Special Parameters 994 Positional Parameters 996 Expanding Null and Unset Variables 1001 Builtin Commands 1002 type: Displays Information About a Command 1003 read: Accepts User Input 1003 exec: Executes a Command or Redirects File Descriptors trap: Catches a Signal 1009 kill: Aborts a Process 1012 getopts: Parses Options... Indexes and the APT Cache 524 The apt cron Script and APT Configuration Files 524 aptitude: Works with Packages and the Local Package Index 526 apt-cache: Displays Package Information 530 apt-get source: Downloads Source Files 532 dpkg: The Debian Package Management System 532 deb Files 533 dpkg: The Foundation of the Debian Package Management System BitTorrent 539 Installing Non-dpkg Software 541... Interfaces: Installer and Installed System 30 Ubuntu Releases 31 Ubuntu Editions 32 Installing a Fresh Copy or Upgrading an Existing Ubuntu System? Setting Up the Hard Disk 33 RAID 40 LVM: Logical Volume Manager 41 The Installation Process 42 Downloading and Burning a CD/DVD 43 The Easy Way to Download a CD ISO Image File 43 Other Ways to Download a CD/DVD ISO Image File 44 Verifying an ISO Image File... Filesystem Parameters RAID Filesystem 514 Chapter Summary 514 Exercises 515 Advanced Exercises 515 xxiii 512 Chapter 13: Downloading and Installing Software 517 JumpStart: Installing and Removing Packages Using aptitude 519 Finding the Package That Holds a File You Need 521 APT: Keeps the System Up -to- Date 522 Repositories 522 sources.list: Specifies Repositories for APT to Search 523 The APT Local Package... Library of WoweBook.Com xx Contents Parameters and Variables 312 User-Created Variables 314 Variable Attributes 317 Keyword Variables 318 Special Characters 326 Processes 328 Process Structure 328 Process Identification 328 Executing a Command 330 History 330 Variables That Control History 330 Reexecuting and Editing Commands 332 The Readline Library 340 Aliases 346 Single Versus Double Quotation Marks... Displays Text 171 date: Displays the Time and Date 172 script: Records a Shell Session 172 todos: Converts Linux and Macintosh Files to Windows Format Compressing and Archiving Files 174 bzip2: Compresses a File 174 bunzip2 and bzcat: Decompress a File 175 gzip: Compresses a File 175 tar: Packs and Unpacks Archives 176 Locating Commands 178 which and whereis: Locate a Utility 178 mlocate: Searches for a. .. 57 ubiquity: Installing Ubuntu Graphically 57 Graphical Partition Editors 63 gparted: The GNOME Partition Editor 64 palimpsest: The GNOME Disk Utility 66 ubiquity: Setting Up Partitions 70 Upgrading to a New Release 74 Installing KDE 75 Setting Up a Dual-Boot System 76 Creating Free Space on a Windows System 76 Installing Ubuntu Linux as the Second Operating System 77 Advanced Installation 77 The Disk... Demand 792 Chapter Summary 795 Exercises 795 Advanced Exercises 795 From the Library of WoweBook.Com xxx Contents Chapter 23: Samba: Linux and Windows File and Printer Sharing 797 Introduction to Samba 798 More Information 799 Notes 799 Samba Users, User Maps, and Passwords 799 Setting Up a Samba Server 800 Prerequisites 800 JumpStart: Configuring a Samba Server Using system-config-samba 800 swat:... Screen as a File 244 The Keyboard and Screen as Standard Input and Standard Output Redirection 245 Pipes 251 Running a Command in the Background 254 Filename Generation/Pathname Expansion 256 The ? Special Character 256 The Special Character 257 The [ ] Special Characters 259 244 * From the Library of WoweBook.Com Contents xix Builtins 261 Chapter Summary 261 Utilities and Builtins Introduced in This Chapter... Programming Language 11 Overview of Linux 12 Linux Has a Kernel Programming Interface 12 Linux Can Support Many Users 13 Linux Can Run Many Tasks 13 Linux Provides a Secure Hierarchical Filesystem 13 The Shell: Command Interpreter and Programming Language 14 A Large Collection of Useful Utilities 16 Interprocess Communication 16 System Administration 17 xiii From the Library of WoweBook.Com xiv Contents Additional . ptg ptg Praise for Previous Editions of A Practical Guide to Ubuntu Linux “I am so impressed by how Mark Sobell can approach a complex topic in such an understandable manner. His command examples are. did not have the guts to do so—until I saw your familiarly titled A Practical Guide to Red Hat ® Linux ® at the bookstore. I picked up a copy and am eagerly looking forward to regaining my. my freedom.” —Carmine Stoffo Machine and Process Designer to pharmaceutical industry “I am currently reading A Practical Guide to Red Hat ® Linux ® and am finally understanding the true