Red hat fedora linux 2 all in one desk reference for dummies (2004)

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummiesx Chapter 2: Installing Fedora Core.. .31 Following the Installation Steps ...31 Checking Your PC’s Hardware ...33 Setting Asi

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

Published by

Wiley Publishing, Inc.

111 River Street

Hoboken, NJ 07030-5774

Copyright © 2004 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 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, e-mail:

permit-brandreview@wiley.com.

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 Red Hat and Fedora are trademarks or registered trademarks of Red Hat, Inc Linux is a registered trademark 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.

LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS

OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERI- ALS THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES

OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ

For general information on our other products and services or to obtain technical support, please tact our Customer Care Department within the U.S at 800-762-2974, outside the U.S at 317-572-3993, or fax 317-572-4002.

con-Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic books.

Library of Congress Control Number is available from the publisher.

ISBN: 0-7645-6793-4

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

1O/SR/QX/QU/IN

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-DOSand Windows to UNIX and Linux He bought his first personal computer — anIBM PC-AT — in 1984 after graduating with a PhD in electrical engineering fromthe University of Maryland at College Park While pursuing a full-time career inengineering, Naba dreamed of writing software for the emerging PC softwaremarket As luck would have it, instead of building a software empire likeMicrosoft, he ended up writing successful computer books Currently, Naba is

a Senior Level Technologist at the Center for Technology and Engineering inthe U.S General Accounting Office

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 bestselling 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 Linux 9 Professional Secrets, also published by Wiley.

Naba lives in North Potomac, Maryland, with his wife Leha, and their dren, Ivy, Emily, and Ashley

I would like to thank Jason Luster for reviewing the manuscript for technicalaccuracy and providing many useful suggestions for improving the book’scontent.

Thanks to everyone at Wiley Publishing for transforming my raw manuscriptinto this well-edited and beautifully packaged book

Of course, there would be no reason for this book if it were not for Linux Forthis, we have Linus Torvalds and the legions of Linux developers around theworld to thank Thanks to Red Hat for providing beta copies of Red Hat Linuxand the publisher’s edition CDs that are bundled with this book

Finally, and as always, my greatest thanks go to my wife, Leha, and ourdaughters, Ivy, Emily, and Ashley — it is their love and support that keeps megoing Thanks for being there!

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: Linda Morris

Acquisitions Editor: Terri Varveris

Copy Editor: Rebecca Senninger

Technical Editor: Jason Luster

Editorial Manager: Leah Cameron

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

Proofreaders: Carl William Pierce,

Sossity Smith, Brian H Walls

Indexer: Lynnzee Elze

Publishing and Editorial for Technology Dummies

Richard Swadley, Vice President and Executive Group Publisher

Andy Cummings, Vice President and Publisher

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

Contents at a Glance

Introduction 1

Book I: Fedora Basics 7

Chapter 1: Introducing Fedora Core .9

Chapter 2: Installing Fedora Core 31

Chapter 3: Troubleshooting and Configuring Fedora Core 57

Chapter 4: Trying Out Fedora Core 75

Chapter 5: Cool Fedora Core Install Projects 99

Book II: Workstations and Applications 109

Chapter 1: Exploring the GUI Desktops .111

Chapter 2: Learning the Shell 135

Chapter 3: Navigating the Linux File System .153

Chapter 4: Exploring Fedora Core Applications 169

Chapter 5: Using Text Editors .199

Book III: OpenOffice.org .211

Chapter 1: Writing with OpenOffice.org Writer .213

Chapter 2: Preparing Spreadsheets with OpenOffice.org Calc 237

Chapter 3: Making Presentations with OpenOffice.org Impress .249

Chapter 4: Drawing with OpenOffice.org Draw .261

Book IV: Networking 269

Chapter 1: Connecting to the Internet .271

Chapter 2: Setting Up a Local Area Network 295

Chapter 3: Adding a Wireless Ethernet LAN .307

Chapter 4: Managing the Network 319

Chapter 5: Cool Networking Projects 329

Book V: Internet .335

Chapter 1: Exchanging E-Mail and Instant Messages 337

Chapter 2: Using the Web .351

Chapter 3: Reading Newsgroups .371

Chapter 4: Transferring Files with FTP .383

Book VI: Administration .391

Chapter 1: Performing Basic System Administration .393

Chapter 2: Managing Users .425

Chapter 3: Managing the File System 437

Chapter 4: Managing Applications .461

Chapter 5: Managing Devices and Printers .479

Chapter 6: Upgrading and Customizing the Kernel 493

Book VII: Security .519

Chapter 1: Understanding Network and Host Security .521

Chapter 2: Securing the Host .535

Chapter 3: Securing the Network .557

Chapter 4: Performing Security Audits 577

Book VIII: Internet Servers .595

Chapter 1: Managing the Servers .597

Chapter 2: Running the Apache Web Server 615

Chapter 3: Setting Up the FTP Server .639

Chapter 4: Serving Up Mail and News 647

Chapter 5: Setting Up DNS 675

Chapter 6: Running Samba and NFS 695

Book IX: Programming .707

Chapter 1: Fedora Core Programming Essentials 709

Chapter 2: Programming in C 735

Chapter 3: Writing Shell Scripts 767

Chapter 4: Programming in Perl .779

Appendix: About the DVD .807

Index 811

Table of Contents

Introduction 1

About This Book 1

Conventions Used in This Book .2

What You Don’t Have to Read .2

Who Are You? .3

How This Book Is Organized 3

What’s on the DVD? .4

Icons Used in This Book 5

Where to Go from Here 5

Book I: Fedora Basics 7

Chapter 1: Introducing Fedora Core .9

What Is Fedora Core? 9

Operating systems and Linux .9

Linux distributions .11

Transitioning to the Fedora Project 11

Making sense of version numbers 12

Under the hood in Linux kernel 2.6 13

What Fedora Core Includes 16

GNU software .16

GUIs and applications .19

Networks 20

Internet servers .21

Software development .22

Online documentation .23

What Fedora Core Helps You Manage .25

Disks, CD-ROMs, and DVD-ROMs .25

Peripheral devices 26

File systems and sharing .27

Network 27

How Do I Get Started? 28

Install 28

Configure 28

Explore 29

Learn 29

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

x

Chapter 2: Installing Fedora Core .31

Following the Installation Steps .31

Checking Your PC’s Hardware .33

Setting Aside Space for Fedora Core .34

Defragmenting your hard disk .34

Resizing your hard disk partition 36

Starting the Fedora Core Installation .39

Selecting Keyboard, Mouse, and Installation Type 40

Partitioning the Disk for Fedora Core 43

Setting Up Key System Parameters 47

Installing the boot loader .47

Configuring the network 48

Configuring the firewall and SELinux .50

Selecting languages to support .51

Setting the time zone .51

Setting the root password .52

Selecting and Installing the Package Groups 53

Chapter 3: Troubleshooting and Configuring Fedora Core .57

Using Text Mode Installation .58

Using the linux noprobe Command .58

Troubleshooting X .59

Resolving Other Installation Problems 61

The fatal signal 11 error 61

Using kernel boot commands .62

Setting Up Printers 64

Turning On Sound .68

Adding User Accounts .69

Managing DVDs and CD-ROMs .71

Installing RPM Packages 72

Chapter 4: Trying Out Fedora Core .75

Booting Fedora Core .75

Exploring GUI Desktops 81

GNOME 81

KDE 88

Playing with the Shell .94

Starting the Bash shell 95

Understanding shell commands 95

Trying a few Linux commands 96

Shutting Down .98

Chapter 5: Cool Fedora Core Install Projects .99

Joining the BitTorrent 99

Things you need .100

Steps to follow .100

Table of Contents xi

Burning Fedora Core CDs 103

Things you need .103

Steps to follow .103

Preparing a Fedora Core DVD 104

Things you need .104

Steps to follow .105

Doing an FTP Install .107

Things you need .107

Steps to follow .107

Book II: Workstations and Applications .109

Chapter 1: Exploring the GUI Desktops .111

Learning the Common Features of the GUIs .111

Desktop pop-up menus 112

Icon pop-up menus 113

The panel 114

The Main Menu .116

Exploring GNOME .119

Using the Nautilus shell .120

Configuring GNOME .124

Exploring KDE 127

Using Konqueror 128

Configuring KDE .132

Chapter 2: Learning the Shell .135

Opening Terminal Windows and Virtual Consoles .135

Using the Bash Shell .136

Learning the syntax of shell commands 136

Combining shell commands 138

Controlling command input and output 138

Typing less with automatic command completion 140

Going wild with asterisks and question marks 140

Repeating previously typed commands .142

Learning Linux Commands .142

Becoming root (superuser) 146

Managing processes 147

Working with date and time .147

Processing files .148

Writing Shell Scripts .151

Chapter 3: Navigating the Linux File System 153

Understanding the Linux File System .153

Navigating the File System with Linux Commands 157

Commands for directory navigation 158

Commands for directory listings and permissions 159

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xii

Commands for changing permissions and ownerships .162

Commands for working with files 163

Commands for working with directories 164

Commands for finding files .165

Commands for mounting and unmounting .166

Commands for checking disk-space usage .167

Chapter 4: Exploring Fedora Core Applications .169

Taking Stock of the Fedora Core Applications .169

Office Applications and Tools .171

Calculators 172

Commercially available office applications for Linux 173

aspell spelling checker .175

Databases 176

Adding a database user .177

Reviewing the steps to build the database .178

Designing the database 179

Creating an empty database .180

Using the PostgreSQL interactive terminal .180

Defining a table .181

Inserting records into a table 182

Querying the database .182

Multimedia Applications .183

Using a digital camera 183

Playing audio CDs 186

Playing sound files .187

Burning a CD .188

Graphics and Imaging .193

The GIMP .194

Gnome Ghostview .196

Chapter 5: Using Text Editors .199

Using GUI Text Editors 199

Text Editing with ed and vi .200

Using ed .201

Using vi .204

Book III: OpenOffice.org .211

Chapter 1: Writing with OpenOffice.org Writer .213

Getting Documents from Others .214

Taking Stock of OpenOffice.org Writer .215

Table of Contents xiii

Getting Started with Writer 216

Examining the Writer main window .217

Setting up Writer 218

Preparing Documents in Writer 221

Editing and reviewing documents .221

Using styles and templates .224

Performing page layout .228

Creating and inserting graphics .231

Using fields .233

Working with large documents .235

Chapter 2: Preparing Spreadsheets with OpenOffice.org Calc .237

Taking Stock of OpenOffice.org Calc 237

Getting Started with Calc .238

Examining the Calc main window .239

Setting up Calc .240

Using Calc 241

Entering and formatting data 241

Calculating and charting data 244

Chapter 3: Making Presentations with OpenOffice.org Impress 249

Taking Stock of OpenOffice.org Impress .249

Getting Started with Impress 250

Using Impress .253

Preparing presentations .254

Adding graphics and special effects .257

Delivering presentations .260

Chapter 4: Drawing with OpenOffice.org Draw .261

Taking Stock of OpenOffice.org Draw .261

Getting Started with Draw 262

Using Draw .264

Book IV: Networking .269

Chapter 1: Connecting to the Internet .271

Understanding the Internet .271

Deciding How to Connect to the Internet .272

Connecting with DSL 274

How DSL works .274

DSL alphabet soup: ADSL, IDSL, SDSL .275

Typical DSL setup 276

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xiv

Connecting with a Cable Modem .279

How cable modem works .280

Typical cable modem setup .282

Setting Up Dial-Up Networking .284

Connecting the modem .286

Testing the modem 289

Setting up and activating a PPP connection .291

Configuring CHAP and PAP authentication .293

Chapter 2: Setting Up a Local Area Network .295

Understanding TCP/IP .295

TCP/IP and the Internet .297

IP addresses .297

Internet services and port numbers .298

Setting Up an Ethernet LAN .299

How Ethernet works 300

Ethernet cables 301

Configuring TCP/IP Networking .302

Connecting Your LAN to the Internet .305

Chapter 3: Adding a Wireless Ethernet LAN .307

Understanding Wireless Ethernet Networks .307

Understanding infrastructure and ad hoc modes .308

Understanding wired equivalent privacy (WEP) 310

Setting Up the Wireless Hardware .310

Configuring the wireless access point .312

Configuring Wireless Networking 312

Chapter 4: Managing the Network .319

Learning the TCP/IP Configuration Files .319

/etc/hosts 320

/etc/networks 320

/etc/host.conf 320

/etc/resolv.conf 321

/etc/hosts.allow 321

/etc/hosts.deny 322

/etc/nsswitch.conf 323

Checking Out TCP/IP Networks 323

Checking the network interfaces 323

Checking the IP routing table 324

Checking connectivity to a host .325

Checking network status .325

Sniffing network packets .327

Configuring Networks at Boot Time .328

Table of Contents xv

Chapter 5: Cool Networking Projects .329

Building Your Own Home Network .329

Things you need .329

Steps to follow .330

Adding Wireless to Your Current Network 331

Things you need .331

Steps to follow .331

Turning Your Fedora Core System into a NAT Router 332

Things you need .332

Steps to follow .333

Book V: Internet 335

Chapter 1: Exchanging E-Mail and Instant Messages 337

Understanding Electronic Mail 338

How MUA and MTA work 338

Mail message enhancements .339

Taking Stock of Mail Readers and IM Clients in Fedora Core .340

Using Ximian Evolution .340

Using Mozilla Mail .344

Managing your Inbox .347

Composing and sending messages .348

Instant Messaging with Gaim 349

Chapter 2: Using the Web .351

Discovering the World Wide Web 351

Like a giant spider’s web .352

Links and URLs .353

Web servers and Web browsers .355

Web Browsing in Fedora Core .356

Checking out the Web browsers in Fedora Core .357

Starting Mozilla 357

Learning Mozilla’s user interface .357

Changing your home page 361

Changing Mozilla’s appearance .361

Surfing the Net with Mozilla 363

Creating Web Pages 364

Introducing HTML .364

Composing Web pages with Mozilla Composer .366

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xvi

Chapter 3: Reading Newsgroups .371

Understanding Newsgroups .371

Newsgroup hierarchy 372

Top-level newsgroup categories 373

Linux-related newsgroups .374

Reading Newsgroups from Your ISP .375

Reading newsgroups with Mozilla Mail .376

Newsgroup subscriptions .378

Posting news .379

Reading and Searching Newsgroups at Web Sites .380

Chapter 4: Transferring Files with FTP .383

Using Graphical FTP Clients .383

Using gFTP 384

Using a Web browser as an FTP client 385

Using the Command-Line FTP Client .387

Book VI: Administration 391

Chapter 1: Performing Basic System Administration .393

Taking Stock of System-Administration Tasks 393

How to Become root .395

Using the su - command .395

Becoming root for the GUI Utilities 395

Recovering from a forgotten root password 396

Understanding How Fedora Core Boots 397

Understanding the init process .397

Examining the /etc/inittab file .399

Trying a new run level with the init command 400

Understanding the Fedora Core startup scripts .401

Manually starting and stopping servers .402

Automatically starting servers at system startup .403

Understanding the GUI startup .404

Taking Stock of Fedora Core System Configuration Files .406

Monitoring System Performance .408

Using the top utility .409

Using the GNOME system monitor .411

Using the uptime command .412

Using the vmstat utility .413

Checking disk performance and disk usage 414

Viewing System Information via the /proc File System .415

Scheduling Jobs in Fedora Core .418

Scheduling one-time jobs .419

Scheduling recurring jobs .421

Table of Contents xvii

Chapter 2: Managing Users .425

Adding User Accounts .425

Using the User Manager to add user accounts 426

Using commands to manage user accounts .428

Understanding the /etc/passwd File 429

Managing Groups .430

Exploring the User Environment 431

Changing User and Group Ownership of Files 434

Chapter 3: Managing the File System .437

Learning the Linux File System .437

Understanding the file-system hierarchy .438

Mounting a device on the file system .440

Examining the /etc/fstab file .442

Sharing Files with NFS .443

Exporting a file system with NFS .444

Mounting an NFS file system 445

Backing Up and Restoring Files 445

Selecting a backup strategy and media .445

Commercial backup utilities for Linux .447

Using the tape archiver — tar 447

Accessing DOS/Windows File Systems 452

Mounting a DOS disk partition .452

Mounting DOS floppy disks 453

Mounting an NTFS Partition 455

Using mtools .455

Trying mtools 456

Understanding the /etc/mtools.conf file .456

Learning the mtools commands .457

Formatting a DOS floppy .459

Chapter 4: Managing Applications .461

Working with Red Hat Package Manager .461

Using the RPM commands .461

Understanding RPM filenames 462

Finding out about RPMs .463

Installing an RPM .466

Removing an RPM .467

Upgrading an RPM 467

Verifying an RPM .468

Building Software Packages from Source Files .469

Downloading and unpacking the software .469

Building the software from source files 471

Installing SRPMS .474

Updating Fedora Core Applications with Up2date .474

Using Yellow dog Updater, Modified (Yum) .475

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xviii

Chapter 5: Managing Devices and Printers 479

Understanding Linux Devices .479

Device files .480

Persistent device naming with udev .482

Managing Loadable Driver Modules .482

Loading and unloading modules .483

Using the /etc/modprobe.conf file .485

Managing USB Devices .486

Managing Print Queues in Fedora Core 488

Spooling and print jobs .488

Printing with the lp command .490

Checking the print queue using lpq .490

Canceling the print job using cancel .490

Checking the printer status using lpstat .491

Controlling the print queue 491

Chapter 6: Upgrading and Customizing the Kernel 493

Upgrading with a Kernel RPM 494

Downloading new kernel RPMs .494

Installing the kernel RPMs 494

Trying out the new kernel .495

Rebuilding the Kernel .496

Creating a monolithic versus a modular kernel .497

Configuring the kernel .498

Running the kernel configuration tool 499

Building the Kernel and the Modules .513

Installing the Modules .514

Creating the Initial RAM Disk File 514

Installing the New Kernel and Setting Up GRUB .515

Rebooting the System 517

Book VII: Security .519

Chapter 1: Understanding Network and Host Security .521

Why Worry About Security? .521

Establishing a Security Framework .522

Determine business requirements for security .523

Perform risk analysis .524

Establish security policy .525

Implement security solutions (mitigation) .526

Manage security .526

Table of Contents xix

Securing Linux .527Understanding the host security issues 527Understanding network security issues 528Learning Computer Security Terminology 529Keeping Up with Security News and Updates .532

Chapter 2: Securing the Host .535

Installing Operating System Updates .535Securing Passwords .536Shadow passwords 536Pluggable authentication modules (PAMs) .537Protecting Files and Directories 540Viewing ownerships and permissions .540Changing file ownerships .541Changing file permissions .541Setting default permission .542Checking for set user ID permission .543Using exec-shield 544Using SELinux .545Encrypting and Signing Files with GnuPG 547Understanding public-key encryption .547Understanding digital signatures .548Using GPG .550Monitoring System Security 554

Chapter 3: Securing the Network .557

Securing Internet Services .557Using chkconfig to disable standalone services .558Configuring the xinetd server to disable services .558Using Secure Shell (SSH) for Remote Logins .561Setting Up Simple Firewalls 563Screening the router with packet filtering .565Dual-homed host .567Perimeter network with bastion host .568Application gateway 570Enabling Packet Filtering on Your Fedora Core System .571Using the security level configuration tool .572Using the iptables command .573

Chapter 4: Performing Security Audits .577

Understanding Security Audits .577Nontechnical aspects of security audits .578Technical aspects of security audits .579

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xx

Learning a Security Test Methodology 579Some common computer vulnerabilities .580Host security review .582Network-security review 585Exploring Security Testing Tools .588Nmap 589Nessus 590SAINT 593SARA 594Book VIII: Internet Servers .595

Chapter 1: Managing the Servers .597

Understanding Internet Services .597TCP/IP and sockets .598Internet services and port numbers .601Using the xinetd Super Server 603Running Standalone Servers 606Starting and stopping servers manually .606Starting servers automatically at boot time .607

Chapter 2: Running the Apache Web Server .615

Exploring HTTP .615Exploring the Apache Web Server .618Installing the Apache Web server .619Starting the Apache Web server 620Configuring the Apache Web Server 621Using Apache configuration tools .622Apache configuration files .623The httpd.conf configuration file .624Virtual host setup 634

Chapter 3: Setting Up the FTP Server .639

Installing the FTP Server .639Configuring the FTP Server 640vsftpd configuration files .640/etc/vsftpd/vsftpd.conf file 641/etc/vsftpd.ftpusers file .643/etc/vsftpd.user_list file 644Setting Up Secure Anonymous FTP .644Trying Anonymous FTP 645Key features of anonymous FTP .645

Table of Contents xxi

Chapter 4: Serving Up Mail and News .647

Installing the Mail Server .647Using sendmail 648

A mail-delivery test .649The mail-delivery mechanism 649The sendmail configuration file 651sendmail.cf file syntax .659Other sendmail files .661The forward file .662Invoking procmail in the forward file 663The sendmail alias file .664Installing the News Server .665Configuring and Starting the INN Server 665InterNetNews components 666The incoming.conf file .670The readers.conf file .671InterNetNews startup .671Setting Up Local Newsgroups 672Defining a newsgroup hierarchy 673Updating configuration files 673Adding the newsgroups .674Testing your newsgroups .674

Chapter 5: Setting Up DNS .675

Understanding Domain Name System (DNS) 675What is DNS? .676Learning hierarchical domain names .677Exploring Berkeley Internet Name Domain (BIND) 678Configuring DNS .682Configuring the resolver 682Configuring a caching name server .683Configuring a primary name server .692

Chapter 6: Running Samba and NFS .695

Sharing Files with NFS .695Exporting a file system with NFS .696Mounting an NFS file system 698Using the NFS Server Configuration tool 699Setting Up a Windows Server Using Samba .700Checking whether Samba is installed .702Configuring Samba .703Trying out Samba .705

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xxii

Book IX: Programming 707

Chapter 1: Fedora Core Programming Essentials .709

Learning Programming .709

A simplified view of a computer .710Role of the operating system .711Basics of computer programming .712Exploring the Software Development Tools in Fedora Core 713GNU C and C++ compilers .714The GNU make utility .718The GNU debugger .725Understanding the Implications of GNU Licenses .732The GNU General Public License 732The GNU Library General Public License 733

Chapter 2: Programming in C .735

The Structure of a C Program .735Preprocessor Directives .737Including files 738Defining macros .738Declaration and Definition of Variables 741Basic data types .741Enumerations 742Structures, Unions, and Bit Fields 743Arrays 743Pointers 744Type definitions .745Type qualifiers: const and volatile .746Expressions 747Operator Precedence 749Statements 751The break statement .751The case statement .752

A compound statement or block 752The continue statement .752The default label 753The do statement .753Expression statements 753The for statement .753The goto statement .754The if statement 754The if-else statement 754The null statement .755The return statement .755

Table of Contents xxiii

The switch statement .755The while statement .756Functions 757Function prototypes 757The void type .758Functions with a variable number of arguments 758The C Library 758Shared Libraries in Linux Applications .760Examining shared libraries that a program uses .760Creating a shared library 762Dynamically loading a shared library 764

Chapter 3: Writing Shell Scripts .767

Trying Out Simple Shell Scripts .767Learning the Basics of Shell Scripting .770Storing stuff .770Calling shell functions 771Controlling the flow 772Exploring Bash’s built-in commands .775

Chapter 4: Programming in Perl 779

Understanding Perl .779Determining Whether You Have Perl 780Writing Your First Perl Script 782Getting an Overview of Perl 783Basic Perl syntax .783Variables 784Operators and expressions .787Regular expressions .789Flow-control statements .791Accessing Linux commands 795File access .797Filename with pipe prefix .798Subroutines 799Built-in functions in Perl .800Understanding Perl Packages and Modules .800Perl packages .801Perl modules .802Using a module .803Using Objects in Perl .804Understanding Perl Objects 804Creating and accessing Perl objects .805Using the English module 806

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

xxiv

Appendix: About the DVD 807

DVD Installation Instructions .807What You Can Find on the DVD 809Troubleshooting 810Index 811

Red Hat has recently decided to discontinue the Red Hat Linux productline and instead focus on the commercial Red Hat Enterprise Linux —RHEL — product line The evolution of the now-defunct Red Hat Linuxproduct line continues on as the Fedora Project, a Red Hat-sponsored andcommunity-supported open source project that continues to evolve whatonce was Red Hat Linux What comes out of the Fedora Project is a FedoraCore release every six months or so (For example, Fedora Core 1 came out

in November 2003 and Fedora Core 2 was released in May 2004.) In contrast

to the rapid Fedora Core release cycles, RHEL is a stable product line with

a 12 to 18 month release cycle and five years of support for every version.New technologies that first appear in Fedora Core will eventually find theirway into the next-generation Red Hat Enterprise Linux (RHEL) product.Thus, Fedora Core releases are a precursor to what’s coming in RHEL inthe future

The recently released Fedora Core 2 comes with many new system nents including the Linux 2.6.5 kernel, X.Org X11 6.7.0, GNOME 2.6, KDE 3.2.2,GCC 3.3 compiler, and the glibc 2.3.3 system libraries This version supportsmany new features such as Advanced Configuration and Power Interface(ACPI), Bluetooth wireless connections, and a graphical boot screen thatshows system startup messages in a user-friendly screen

compo-Fedora Core 2 also includes the OpenOffice.org 1.1.1 office suite To top itoff, Fedora Core continues to come with a graphical installation programthat makes installation easy!

About This Book

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies gives you

nine different quick-reference guides in a single book Taken together, thesenine books provide detailed information on installing, configuring, andusing Fedora Core

What you’ll like most about this book is that you don’t have to read itsequentially chapter by chapter, or, for that matter, even the sections in

a chapter You can pretty much turn to the topic you want and quickly getthe answer to your pressing questions about Fedora Core, be it about usingthe OpenOffice.org word processor or setting up the Apache Web server

Conventions Used in This Book

2

Here are some of the things you can do with this book:

✦ Install and configure Fedora Core from the DVD-ROM included with thebook

✦ Connect the Fedora Core PC to the Internet through a DSL or cablemodem

✦ Set up dial-up networking with PPP

✦ Get tips, techniques, and shortcuts for specific uses of Fedora Core,such as

• Setting up and using Internet services such as Web, Mail, News, FTP,NFS, and DNS

• Setting up a Windows server using Samba

• Using Linux commands

• Using Perl, shell, and C programming on Linux

• Using the OpenOffice.org office suite and other applications thatcome with Fedora Core

✦ Understand the basics of system and network security

✦ Perform system administration tasks

Conventions Used in This Book

I use a simple notational style in this book All listings, filenames, functionnames, variable names, and keywords are typeset in a monospacefont forease of reading I italicize the first occurrences of new terms and conceptsand then provide a definition right there The output of commands followsthe typed command and the output is shown in a monospace font

What You Don’t Have to Read

Each mini reference book zeros in on a specific task area such as using theInternet or running Internet servers and then provides hands-on instructions

on how to perform a series of related tasks You can jump right to a sectionand read about a specific task You don’t have to read anything but the fewparagraphs or the list of steps that relate to your question Use the Table ofContents or the Index to locate the pages relevant to your question

You can safely ignore text next to the Technical Stuff icons as well as thesidebars

How This Book Is Organized 3

Who Are You?

I assume that you are somewhat familiar with a PC — you know how to turn

it on and off and you have dabbled a bit with Windows Considering thatmost new PCs come preloaded with Windows, this assumption is safe, right? When installing Fedora Core on your PC, you may want to retain your

Windows 2000 or Windows XP installations intact I assume you don’t

mind investing in a good disk-partitioning tool such as PowerQuest’s

PartitionMagic, available at www.powerquest.com/partitionmagic

(no, I don’t have any connections with PowerQuest)

I also assume that you are willing to accept the risk that when you try toinstall Fedora Core, some things may not quite work Problems can happen

if you have some uncommon types of hardware If you are afraid of ruiningyour system, try finding a slightly older spare Pentium PC that you can sac-rifice and then install Fedora Core on that PC

How This Book Is Organized

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies has nine books,

each of which focuses on a small set of related topics If you are looking forinformation on a specific topic, check the book names on the spine or con-sult the Table of Contents

This desk reference starts with a minibook that explains the basics of FedoraCore and guides you through the installation process (a unique aspect ofthis book because you typically do not purchase a PC with Fedora Core pre-installed) The second minibook serves as a user’s guide to Fedora Core — itfocuses on exploring various aspects of a Fedora Core workstation, includingthe GNOME and KDE GUIs and many of the applications that come bundledwith Fedora Core The third minibook is a user’s guide to the OpenOffice.orgoffice applications The fourth minibook covers networking and Book V goesinto using the Internet Book VI introduces system administration The sev-enth minibook turns to the important subject of securing a Fedora Coresystem and its associated network Book VIII shows you how to run a vari-ety of Internet servers from mail to a Web server The ninth and final mini-book introduces you to programming

Here’s a quick overview of the nine books and what they contain:

Book I: Fedora Basics: What is Fedora Core? Understanding what’s new in

the Linux 2.6 kernel Installing, configuring, and troubleshooting FedoraCore Taking Fedora Core for a test drive

What’s on the DVD?

4

Book II: Workstations and Applications: Exploring GNOME and KDE Using

the shell (what’s a shell anyway?) Navigating the Fedora Core file system.Exploring the applications such as multimedia software as well as the texteditors (viand ed)

Book III: OpenOffice.org: Writing with OpenOffice.org Writer Preparing

spreadsheets with OpenOffice.org Calc Making presentations with

OpenOffice.org Impress Preparing drawings with OpenOffice.org Draw

Book IV: Networking: Connecting the Fedora Core PC to the Internet through

a dial-up connection or a high-speed always-on connection such as DSL orcable modem Configuring and managing TCP/IP networks, including wire-less networks

Book V: Internet: Using various Internet services such as e-mail, Web

surf-ing, and reading newsgroups Transferring files with FTP

Book VI: Administration: Performing basic system administration Managing

user accounts and the file system Installing applications Working withdevices and printers Using USB devices Upgrading and customizing theLinux kernel

Book VII: Security: Understanding network and host security Securing the

host and the network Performing security audits

Book VIII: Internet Servers: Managing the Internet services Configuring the

Apache Web server Setting up the FTP server (including anonymous FTP).Configuring the mail and news servers Providing DNS File sharing with NFS.Using Samba to set up a Windows server

Book IX: Programming: Finding out the basics of programming Exploring the

software development tools in Fedora Core Writing shell scripts Learning Cand Perl programming

Appendix: About the DVD: Summarizes the contents of the book’s

compan-ion DVD-ROM

What’s on the DVD?

The DVD contains Fedora Core 2 from the Fedora Project (fedora.redhat.com) You may use the DVD in accordance with the license agreementsaccompanying the software To discover more about the contents of the DVD,please consult the appendix

Where to Go from Here 5

Icons Used in This Book

Following the time-honored tradition of the All-in-One Desk Reference For

Dummies series, I use icons to help you quickly pinpoint useful information.

The icons include the following:

The Remember icon marks a general interesting fact — something that Ithought you want to know and remember

The Tip icon marks things that you can do to make your job easier

The Warning icon highlights potential pitfalls With this icon, I’m telling you:

“Watch out! This could hurt your system!”

The Technical Stuff icon marks technical information that could be of est to an advanced user (or those of us aspiring to be advanced users)

inter-Where to Go from Here

It’s time to get started on your Fedora Core adventure Take out the DVDand install Fedora Core Then, turn to a relevant chapter and let the funbegin Use the Table of Contents and the Index to figure out where you want

to go Before you know it, you’ll become an expert at Fedora Core!

If you want to participate in the Fedora Core project, visit the project’s Website at fedora.redhat.comfor more information

I hope you enjoy consulting this book as much as I enjoyed writing it!

Sidebars

I use sidebars throughout the book to highlight

interesting, but not critical, information Sidebars

explain concepts you may not have encountered

before or give a little insight into a related topic

If you’re in a hurry, you can safely skip thesidebars

Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies

6

Book I

Fedora Basics

Contents at a Glance

Chapter 1: Introducing Fedora Core 9 Chapter 2: Installing Fedora 31 Chapter 3: Troubleshooting and Configuring Fedora Core 57 Chapter 4: Trying Out Fedora Core 75 Chapter 5: Cool Fedora Install Projects 99

Chapter 1: Introducing Fedora Core

In This Chapter

Explaining what Fedora Core is

Going over what Fedora Core includes

Discovering what Fedora Core helps you manage

Getting started

Ibet you’ve heard about Linux and you probably know about Red Hat

Linux as well, but chances are Fedora Core is new to you If you’re dering what exactly Fedora Core is and what it can help you do, this chapter

won-is all about answering those questions Here I provide a broad-brushstrokepicture of Fedora Core and tell you how you can start using it right away

By the way, this book covers Fedora Core for Intel 80x86 and Pentiumprocessors (basically any PC that can run any flavor of Windows)

What Is Fedora Core?

Fedora Core is what used to be Red Hat Linux — the Linux distribution fromRed Hat that used to be available free of charge If you never knew Red HatLinux, think of Fedora Core as another Linux distribution That leaves youwith the question: What is a Linux distribution anyway?

Trying to describe a Linux distribution is a bit like that story of six blindmen trying to describe an elephant You know the one — one blind mantouches the elephant’s side and says the elephant is like a wall, anotherchecks out the tusk and concludes that an elephant is like a spear, and so

on Along those lines, a Linux distribution appears to be many differentthings, depending on what you experience You can think of it as the graph-ical user interface or just a PC to run your e-mail program, but, at its heart,it’s an operating system The following sections explain what I mean by thisstatement

Operating systems and Linux

You know that your PC is a bunch of hardware — things you can touch, like

the system box, monitor, keyboard, and mouse The system box contains

the most important hardware of all — the central processing unit (CPU), the microchip that runs the software (any program that tells the computer how

What Is Fedora Core?

10

to do your bidding) — which you actually can’t touch In a typical Pentium 4

PC, the Pentium 4 microprocessor is the CPU Other important hardware inthe system box includes the memory (RAM chips) and the hard drive — andone program has to run all this stuff and get it to play nice: the operatingsystem

The operating system is software that manages all the hardware and runs

other software at your command You, the user, provide those commands

by clicking menus and icons or by typing some cryptic text Linux is an ating system — as are UNIX, Windows 98, Windows 2000, and Windows XP.The Linux operating system is modeled after UNIX; in its most basic, no-frills

oper-form, it also goes by the name Linux kernel.

The operating system is what gives a computer — any computer — its sonality For example, you can run Windows 98 or Windows XP on a PC —

per-and on that same PC, you can also install per-and run Linux That means, ing on which operating system is installed and running, the same PC can be

depend-a Windows 98, Windows XP, or Linux system

The primary job of an operating system is to load software (computer grams) from the hard disk (or other permanent storage) into the memoryand get the CPU to run those programs Everything you do with your com-puter is possible because of the operating system — so if the operatingsystem somehow messes up, the whole system freezes up You know howinfuriating it is when your favorite operating system — maybe even the onethat came with your PC — suddenly calls it quits just as you are about toclick the Send button after composing that long e-mail to your friend You trythe three-finger salute (pressing Ctrl+Alt+Del), but nothing happens Thenit’s time for the Reset button (provided your computer’s builders were wiseenough to include one) Luckily, that sort of thing almost never happenswith Linux — it has a reputation for being a very reliable operating system

pro-Does Linux really run on any computer?

Linux runs on many different types of computer

systems — and it does seem able to run on

nearly any type of computer Linus Torvalds and

other programmers originally developed Linux

for the Intel 80x86 (and compatible) line of

processors Nowadays, Linux is also available

for systems based on other processors — such

as those with AMD’s 64-bit AMD64 processors,

the Motorola 68000 family; Alpha AXPs; Sun

SPARCs and UltraSPARCs; Hewlett-Packard’s

HP PA-RISC; the PowerPC and PowerPC64processors; and the MIPS R4x00 and R5x00.More recently, IBM has released its own ver-sion of Linux for its S/390 mainframe This bookcovers Linux for Intel 80x86 and Pentium proces-sors (these have in common a basic physical

structure known as IA-32 architecture).

Book I Chapter 1

What Is Fedora Core? 11

In technical mumbo jumbo, Linux is a multiuser, multitasking operating system.

All this means is that Linux enables multiple users to log in, and Linux can

run more than one program at the same time Nearly all operating systems

are multiuser and multitasking these days, but when Linux first started in

1994, multiuser and multitasking were big selling points.

Linux distributions

Fedora Core is a specific Linux distribution — essentially a package of

fea-tures Fedora Core consists of the Linux kernel (the operating system) and

a collection of applications, together with an easy-to-use GUI installation

program, called Anaconda

You find many Linux distributions, and each includes the standard Linux

operating system:

✦ The X.Org X Window System: The graphical user interface.

✦ One or more graphical desktops: Among the most popular are GNOME

and KDE

✦ A selection of applications: Linux programs come in the form of

ready-to-run software, but the source code (the commands we humans use to tell

the computer what to do, but you don’t need the source code to run the

operating system or any applications) is included, as is its documentation

Current Linux distributions include a huge selection of software — so

much that it requires multiple CD-ROMs or a single DVD-ROM (which

this book includes)

Many Linux distributions are commercial products that you can buy in

com-puter stores and bookstores If you have heard about Open Source and the

GNU (GNU’s Not UNIX) license, you may assume that no one can sell Linux

for profit Luckily for companies that sell Linux distributions, the GNU

license — also called the GNU General Public License (GPL) — does allow

commercial, for-profit distribution, but requires that the software be

dis-tributed in source-code form, and stipulates that anyone may copy and

distribute the software in source-code form to anyone else Fedora Core

is available free of charge under the GPL, which means that my publisher

may include the Fedora Core DVD-ROM with this book and you may make

as many copies of the DVD as you like

Transitioning to the Fedora Project

In late September 2003, Red Hat announced the Fedora Project — an

open-source project sponsored by Red Hat where the developer community can

participate and continue to evolve what used to be the Red Hat Linux

prod-uct The new product goes by the name Fedora Core and the project is

expected to have Fedora Core releases every four to six months Red Hat

What Is Fedora Core?

12

continues to participate in the Fedora Project and help prepare the FedoraCore releases, but everything is done with involvement of the open sourcecommunity under a public release schedule As you may expect, Fedora Core

is available freely, just as Red Hat Linux used to be, and you can expect bookssuch as this one to include Fedora Core on DVD or CDs

Red Hat continues to sell its commercial Linux distribution — called Red HatEnterprise Linux Red Hat anticipates that new technologies and enhance-ments that first appear in Fedora Core will eventually find their way into RedHat Enterprise Linux In this way, the Fedora Project serves as an incubatorand testing ground for future Linux development

To find out more about the Fedora Project, visit fedora.redhat.com

Making sense of version numbers

Both the Linux kernel and Fedora Core have their own version numbers, not

to mention the many other software programs (such as GNOME and KDE)that come with Fedora Core The version numbers for the Linux kernel andFedora Core are unrelated, but each has particular significance

Linux-kernel version numbers

After Linux kernel version 1.0 was released on March 14, 1994, the looselyknit Linux development community adopted a version-numbering scheme

Version numbers such as 1.X.Y and 2.X.Y, where X is an even number, are considered the stable versions The last number, Y, is the patch level, which

is incremented as problems are fixed For example, 2.6.5 is a typical, stableversion of the Linux kernel Notice that these version numbers are in the

form of three integers separated by periods — Major.Minor.Patch — where

Major and Minor are numbers denoting the major and minor version

num-bers, and Patch is another number representing the patch level.

Version numbers of the form 2.X.Y with an odd X number are beta releases

for developers only; they may be unstable, so you should not adopt suchversions for day-to-day use For example, when you look at version 2.5.75 of

the Linux kernel, notice the 5 — that tells you it’s a beta release Developers

add new features to these odd-numbered versions of Linux

You can find out about the latest version of the Linux kernel online at

www.kernel.org

Fedora Core version numbers

The Fedora Core development community, led by Red Hat, assigns the Fedora

Core version numbers, such as 1 or 2 They are of the form X.Y, where X is the major version and Y the minor version Nowadays if the minor version

number is zero, it’s simply dropped — as in Fedora Core 1 and Fedora Core 2

Book I Chapter 1

What Is Fedora Core? 13

Unlike with the Linux-kernel version numbers, no special meaning is

associ-ated with odd and even minor versions Each version of Fedora Core includes

specific versions of the Linux kernel and other major components, such as

GNOME, KDE, and various applications

The Fedora Project releases new versions of Fedora Core on a regular

basis — every six months or so For example, Fedora Core 1 came out in

November 2003 and Fedora Core 2 in May 2004 Typically, each new major

version of Fedora Core provides significant new features

Under the hood in Linux kernel 2.6

Linux kernel 2.6 includes many new features and improvements when

com-pared to its predecessor — the 2.4 kernel I highlight some of these

improve-ments in this section You may not notice many of these improveimprove-ments

because they work behind the scenes All you see is a Linux system that

simply works great!

Support for wider range of computer hardware

For starters, the 2.6 kernel has been redesigned to support computers

span-ning a wider range of hardware than before — from bare-bones embedded

microcontrollers to larger-scale servers with multiple processors

To support distinct hardware architectures of the same processor family

(such as x86), Linux 2.6 uses the concept of a subarchitecture, which refers

to the processor and the associated bus and other hardware that defines a

unique type of computer For example, most of today’s PCs are based on

what is called the PC/AT subarchitecture because these PCs are based on

the original IBM PC/AT The 2.6 kernel supports PC/AT machines as well

as other x86 subarchitectures, such as the NEC Voyager and the PC-9800

machines The bottom line is that the 2.6 kernel can run on many variations

of the x86-based machines

Linux 2.6 also supports advanced features of processors such as

hyperthread-ing, which enables a single processor to act as multiple virtual processors at

the hardware level

Better scalability

The 2.6 kernel provides better scalability for Intel x86 hardware by

support-ing advanced features such as Intel’s Physical Address Extension (PAE), which

enables many newer 32-bit x86 systems to access up to 64GB of memory

Linux 2.6 also provides better handling of interrupts for multiprocessor

sys-tems through improved support for Intel’s Input/Output (I/O) Advanced

Programmable Interrupt Controller (APIC)