by Naba Barkakati Linux ® ALL-IN-ONE DESK REFERENCE FOR DUMmIES ‰ 2ND EDITION 01_752622 ffirs.qxp 3/29/06 12:08 AM Page i Linux ® All-in-One Desk Reference For Dummies, ® 2nd Edition Published by Wiley Publishing, Inc. 111 River Street Hoboken, NJ 07030-5774 www.wiley.com Copyright © 2006 by Wiley Publishing, Inc., Indianapolis, Indiana Published by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permit- ted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Legal Department, Wiley Publishing, Inc., 10475 Crosspoint Blvd., Indianapolis, IN 46256, (317) 572-3447, fax (317) 572-4355, or online at http://www.wiley.com/go/permissions. Trademarks: Wiley, the Wiley Publishing logo, For Dummies, the Dummies Man logo, A Reference for the Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies.com, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission. Linux is a registered trade- mark of Linus Torvalds. All other trademarks are the property of their respective owners. Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book. 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Library of Congress Control Number: 2005931152 ISBN-13: 978-0-471-75262-2 ISBN-10: 0-471-75262-2 Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 2B/RY/QU/QW/IN 01_752622 ffirs.qxp 3/29/06 12:08 AM Page ii About the Author Naba Barkakati is an electrical engineer and a successful computer-book author who has experience in a wide variety of systems, ranging from MS-DOS and Windows to UNIX and Linux. He bought his first personal computer — an IBM PC-AT — in 1984 after graduating with a PhD in electrical engineering from the University of Maryland at College Park. While pursuing a full-time career in engineering, Naba dreamed of writing software for the emerging PC software market. As luck would have it, instead of building a software empire like Microsoft, he ended up writing successful computer books. Currently, Naba is a Senior Level Technologist at the Center for Technology and Engineering in the U.S. Government Accountability Office (GAO). Over the past 15 years, Naba has written over 25 computer books on a number of topics, ranging from Windows programming with C++ to Linux. He has authored several best-selling titles, such as The Waite Group’s Turbo C++ Bible, Object-Oriented Programming in C++, X Window System Programming, Visual C++ Developer’s Guide, Borland C++ 4 Developer’s Guide, and Linux Secrets. His books have been translated into many languages, including Spanish, French, Polish, Greek, Italian, Chinese, Japanese, and Korean. Naba’s most recent book is Red Hat Fedora Linux Secrets, also pub- lished by Wiley Publishing, Inc. Naba lives in North Potomac, Maryland, with his wife Leha, and their children, Ivy, Emily, and Ashley. 01_752622 ffirs.qxp 3/29/06 12:08 AM Page iii Dedication I would like to dedicate this book to my wife Leha, and daughters Ivy, Emily, and Ashley. 01_752622 ffirs.qxp 3/29/06 12:08 AM Page v Author’s Acknowledgments I am grateful to Terri Varveris for getting me started on this book — a set of eight quick reference guides about Linux that focuses on several major Linux distributions. As the project editor, Christopher Morris guided me through the manuscript-submission process and kept everything moving. I appreciate the guidance and support that Terri and Chris gave me during this project. I would like to thank Jason Luster for reviewing the manuscript for technical accuracy and providing many useful suggestions for improving the book’s content. Thanks to everyone at Wiley Publishing for transforming my raw manuscript into this well-edited and beautifully packaged book. Of course, there would be no reason for this book if it were not for Linux. For this, we have Linus Torvalds and the legions of Linux developers around the world to thank. Finally, and as always, my greatest thanks go to my wife, Leha, and our daughters, Ivy, Emily, and Ashley — it is their love and sup- port that keeps me going. Thanks for being there! 01_752622 ffirs.qxp 3/29/06 12:08 AM Page vii Publisher’s Acknowledgments We’re proud of this book; please send us your comments through our online registration form located at www.dummies.com/register/. Some of the people who helped bring this book to market include the following: Acquisitions, Editorial, and Media Development Project Editor: Christopher Morris Acquisitions Editor: Terri Varveris Copy Editor: Heidi Unger Technical Editor: Dan DiNicolo Editorial Manager: Kevin Kirschner Permissions Editor: Laura Moss Media Development Specialist: Travis Silvers Media Development Manager: Laura VanWinkle Media Development Supervisor: Richard Graves Editorial Assistant: Amanda Foxworth Cartoons: Rich Tennant ( www.the5thwave.com) Composition Services Project Coordinator: Erin Smith Layout and Graphics: Andrea Dahl, Denny Hager, Melanee Prendergast, Heather Ryan, Erin Zeltner Proofreaders: Vicki Broyles, Joe Niesen Indexer: Johnna VanHoose Publishing and Editorial for Technology Dummies Richard Swadley, Vice President and Executive Group Publisher Andy Cummings, Vice President and Publisher Mary Bednarek, Executive Acquisitions Director Mary C. Corder, Editorial Director Publishing for Consumer Dummies Diane Graves Steele, Vice President and Publisher Joyce Pepple, Acquisitions Director Composition Services Gerry Fahey, Vice President of Production Services Debbie Stailey, Director of Composition Services 01_752622 ffirs.qxp 3/29/06 12:08 AM Page viii Contents at a Glance Introduction 1 Book I: Linux Basics 7 Chapter 1: Introducing Linux 9 Chapter 2: Installing Linux 31 Chapter 3: Troubleshooting and Configuring Linux 81 Chapter 4: Trying Out Linux 111 Book II: Linux Desktops 131 Chapter 1: Introducing the GUI Desktops 133 Chapter 2: Commanding the Shell 161 Chapter 3: Navigating the Linux File System 181 Chapter 4: Introducing Linux Applications 207 Chapter 5: Using Text Editors 239 Book III: Networking 251 Chapter 1: Connecting to the Internet 253 Chapter 2: Setting Up a Local Area Network 275 Chapter 3: Adding a Wireless Ethernet LAN 287 Chapter 4: Managing the Network 299 Book IV: Internet 311 Chapter 1: E-Mailing and IMing in Linux 313 Chapter 2: Browsing the Web 333 Chapter 3: Reading Newsgroups and RSS Feeds 345 Chapter 4: Using FTP 361 Book V: Administration 371 Chapter 1: Introducing Basic System Administration 373 Chapter 2: Managing Users and Groups 413 Chapter 3: Managing File Systems 425 Chapter 4: Installing and Updating Applications 449 Chapter 5: Customizing the Linux Kernel 473 02_752622 ftoc.qxp 4/4/06 9:11 AM Page ix Book VI: Security 497 Chapter 1: Introducing Linux Security 499 Chapter 2: Securing a Linux Host 513 Chapter 3: Improving Network Security 529 Chapter 4: Performing Computer Security Audits 547 Book VII: Internet Servers 563 Chapter 1: Managing Internet Services 565 Chapter 2: Running a Web Server 583 Chapter 3: Setting Up the FTP Server 607 Chapter 4: Managing Mail and News Servers 613 Chapter 5: Managing DNS 639 Chapter 6: Using Samba and NFS 661 Book VIII: Programming 671 Chapter 1: Programming in Linux 673 Chapter 2: Programming in C 699 Chapter 3: Writing Shell Scripts 731 Chapter 4: Programming in Perl 743 Appendix 771 Index 777 02_752622 ftoc.qxp 4/4/06 9:11 AM Page x Table of Contents Introduction 1 About This Book 2 Conventions Used in This Book 3 What You Don’t Have to Read 3 Who Are You? 3 How This Book Is Organized 4 What’s on the DVD? 5 Icons Used in This Book 5 Where to Go from Here 6 Book I: Linux Basics 7 Chapter 1: Introducing Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 What Is Linux? 9 Linux distributions 10 Making sense of version numbers 14 Linux Standard Base (LSB) 15 What a Linux Distribution Includes 16 GNU software 17 GUIs and applications 19 Networks 21 Internet servers 21 Software development 22 Online documentation 23 What Linux Helps You Manage 24 Disks, CD-ROMs, and DVD-ROMs 25 Peripheral devices 26 File systems and sharing 26 Network 27 Getting Started 27 Install 27 Configure 28 Explore 28 Find out more 29 Chapter 2: Installing Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Following the Installation Steps 32 Checking Your PC’s Hardware 34 Trying Out the Knoppix Live CD 36 Burning CDs or DVDs from ISO Images 37 02_752622 ftoc.qxp 4/4/06 9:11 AM Page xi Linux All-in-One Desk Reference For Dummies, 2nd Edition xii Using a CD burner application 37 Using Knoppix to burn CDs or DVDs 38 Setting Aside Space for Linux 39 Resizing a Windows partition using PartitionMagic 40 Resizing a partition with QTParted in Knoppix 41 Installing Debian GNU/Linux 42 Getting an overview of the installation 43 Completing the Debian installation 44 Installing Fedora Core 48 Selecting keyboard and installation type 49 Partitioning the hard drive for Fedora Core 50 Setting up key system parameters 51 Selecting and installing the package groups 54 Configuring the firewall and SELinux after first boot 56 Installing MEPIS 57 Installing SUSE Linux 60 Performing an FTP install 60 Installing SUSE Linux from CDs 63 Starting the SUSE install in YaST 65 Installing Ubuntu 71 Installing Xandros Desktop 73 Using Xandros Express Install 75 Using Xandros Custom Install 76 Chapter 3: Troubleshooting and Configuring Linux . . . . . . . . . . . . . . . .81 Using Text Mode Installation 82 Troubleshooting X 82 Resolving Other Installation Problems 84 Using Knoppix boot commands 84 The fatal signal 11 error 86 Getting around the PC reboot problem 87 Using Linux kernel boot options 87 Setting Up Printers 90 Configuring printers in Debian 90 Configuring printers in Fedora Core 92 Configuring printers in Knoppix and MEPIS 94 Configuring printers in SUSE 97 Configuring printers in Ubuntu 99 Configuring printers in Xandros 100 Managing DVDs and CD-ROMs 103 Installing Other Software 103 Installing software in Debian, MEPIS, and Ubuntu 104 Installing software in Fedora Core 106 Installing software in SUSE 107 Installing software in Xandros 108 02_752622 ftoc.qxp 4/4/06 9:11 AM Page xii [...]... use Linux for a specific task, such as setting up a Web server or developing software You may also want to try out different Linux distributions before settling on one that you like 2 About This Book Accordingly, Linux All-in-One Desktop Reference For Dummies comes with a DVD that includes seven different Linux distributions — Debian GNU /Linux 3.1r0, Fedora Core 5, Knoppix 4.0.2, MEPIS 3.3.1, SUSE Linux. .. book’s DVD for a quick, no-risk Linux experience.) About This Book Linux All-in-One Desk Reference For Dummies gives you eight different quickreference guides in a single book Taken together, these eight minibooks provide detailed information on installing, configuring, and using Linux What you’ll like most about this book is that you don’t have to read it sequentially chapter by chapter, or for that... 169 Discovering and Using Linux Commands 170 Becoming root (superuser) .173 Managing processes 174 Working with date and time 175 Processing files 176 Writing Shell Scripts 179 xiv Linux All-in-One Desk Reference For Dummies, 2nd Edition Chapter 3: Navigating the Linux File System 181 Understanding the Linux File System 181... an easy-to-use installer and with KDE as the default desktop Until recently, this distribution was called Mandrakelinux Mandriva Linux uses the Red Hat Package Manager (RPM) format for its software packages You can get the Mandriva Linux Download Edition (a 3-CD/DVD set) at www.mandrivalinux.com Click the Download link for more information MEPIS Linux This Debian-based Live CD distribution was first... the File System with Linux Commands 194 Commands for directory navigation 195 Commands for directory listings and permissions 196 Commands for changing permissions and ownerships 199 Commands for working with files 200 Commands for working with directories .201 Commands for finding files .202 Commands for mounting and unmounting .203 Commands for checking disk-space... sell Linux for profit Luckily for companies that sell Linux distributions, the GNU license — also called the Book I Chapter 1 Introducing Linux Distribution 14 What Is Linux? GNU General Public License (GPL) — does allow commercial, for- profit distribution (but requires that the software be distributed in source-code form) and stipulates that anyone may copy and distribute the software in sourcecode form... Security Terminology 507 Keeping Up with Security News and Updates 511 Chapter 2: Securing a Linux Host 513 Securing Passwords .513 Shadow passwords 514 Pluggable authentication modules (PAMs) .515 xx Linux All-in-One Desk Reference For Dummies, 2nd Edition Protecting Files and Directories .516 Viewing ownerships and permissions .516... want to go Before you know it, you’ll become an expert at Linux! I hope you enjoy consulting this book as much as I enjoyed writing it! Book I Linux Basics Contents at a Glance Chapter 1: Introducing Linux 9 Chapter 2: Installing Linux 31 Chapter 3: Troubleshooting and Configuring Linux 81 Chapter 4: Trying Out Linux 111 Chapter 1: Introducing Linux In This... Have Perl .744 Writing Your First Perl Script 745 xxiv Linux All-in-One Desk Reference For Dummies, 2nd Edition Getting an Overview of Perl 746 Basic Perl syntax 747 Variables 747 Operators and expressions .751 Regular expressions 752 Flow-control statements 755 Accessing Linux commands 758 File access 760 Filename with... Devices 401 Device files 401 Persistent device naming with udev .403 xviii Linux All-in-One Desk Reference For Dummies, 2nd Edition Managing Loadable Driver Modules 404 Loading and unloading modules 404 Using the /etc/modprobe.conf file 405 Scheduling Jobs in Linux 407 Scheduling one-time jobs 407 Scheduling recurring jobs 409 Chapter . by Naba Barkakati Linux ® ALL-IN-ONE DESK REFERENCE FOR DUMmIES ‰ 2ND EDITION 01_752622 ffirs.qxp 3/29/06 12:08 AM Page i Linux ® All-in-One Desk Reference For Dummies, ® 2nd Edition Published. 4/4/06 9:11 AM Page xi Linux All-in-One Desk Reference For Dummies, 2nd Edition xii Using a CD burner application 37 Using Knoppix to burn CDs or DVDs 38 Setting Aside Space for Linux 39 Resizing. AM Page xiii Linux All-in-One Desk Reference For Dummies, 2nd Edition xiv Chapter 3: Navigating the Linux File System . . . . . . . . . . . . . . . . . . . .181 Understanding the Linux File System