Beginning Red Hat Linux 9

458 Pages·2003·9.079 MB·English

by  Sandip Bhattacharya, Mark Mamone, Kapil Sharma, Deepak Thomas, Simon Whiting, Shishir Gundavaram

Table of Contents
Beginning Red Hat Linux 9...............................................................................................................................1
Introduction.........................................................................................................................................................4
Who Is This Book For?...........................................................................................................................4
What You Need to Use This Book.........................................................................................................4
What Is Linux?........................................................................................................................................5
Linus Torvalds and the Birth of Linux.............................................................................................5
Why Choose Linux?.........................................................................................................................6
What Is Red Hat Linux 9?................................................................................................................7
What Is Covered in This Book?..............................................................................................................8
Conventions in This Book......................................................................................................................9
Customer Support.................................................................................................................................10
Source Code and Updates...............................................................................................................10
Errata..............................................................................................................................................11
Technical Support...........................................................................................................................11
p2p.wrox.com.................................................................................................................................11
Chapter 1: Installing Red Hat Linux 9..........................................................................................................13
Overview...............................................................................................................................................13
Preparing for the Installation................................................................................................................14
The Software..................................................................................................................................14
The Hardware.................................................................................................................................14
Network Details..............................................................................................................................16
Getting Help...................................................................................................................................17
The Installation.....................................................................................................................................17
Booting off the CD.........................................................................................................................17
Testing the Media...........................................................................................................................18
The Graphical Installation Launch.................................................................................................20
Selecting the Default Language.....................................................................................................21
Selecting the Keyboard..................................................................................................................21
Selecting the Mouse.......................................................................................................................22
Selecting an Installation Type........................................................................................................22
Setting up the Disk Partitions.........................................................................................................23
Setting the Boot Loader..................................................................................................................25
Setting the Network Parameters.....................................................................................................26
Setting up the Firewall...................................................................................................................28
Setting Additional Language Support............................................................................................29
Setting the Time Zone....................................................................................................................30
Root Account Configuration..........................................................................................................30
Selecting Packages for Installation.................................................................................................31
The Automatic Installation Process................................................................................................32
Creating a Boot Disk......................................................................................................................33
Setting up the GUI..........................................................................................................................34
Finishing.........................................................................................................................................36
Booting Up.....................................................................................................................................36
First Boot........................................................................................................................................36
Logging In......................................................................................................................................39
Summary...............................................................................................................................................40
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Table of Contents
Chapter 2: Red Hat Linux 9 Basics................................................................................................................41
Overview...............................................................................................................................................41
Moving Around the Desktop................................................................................................................41
Using Applications.........................................................................................................................43
Shutting Down the Computer.........................................................................................................49
The File System....................................................................................................................................50
The File System Hierarchy.............................................................................................................50
Adding Devices to the Filesystem..................................................................................................54
Navigating in the File System........................................................................................................57
Managing the Hardware........................................................................................................................60
Finding the Existing Hardware.......................................................................................................61
Configuring the Desktop.......................................................................................................................71
Using the Desktop Control Center.................................................................................................71
Managing Processes..............................................................................................................................73
Managing Users....................................................................................................................................78
Summary...............................................................................................................................................80
Chapter 3: Connecting to the Internet...........................................................................................................82
Overview...............................................................................................................................................82
Connecting to the Internet.....................................................................................................................82
Network Configuration Tool..........................................................................................................83
Analog Modem Connections..........................................................................................................84
High−bandwidth Connections........................................................................................................86
Connecting to a LAN.....................................................................................................................88
Other Connection Types.................................................................................................................89
Managing Multiple ISPs and Connections...........................................................................................90
Software and Configuration..................................................................................................................94
Web Browsers................................................................................................................................94
E−mail and News Clients...............................................................................................................97
Other Software...............................................................................................................................99
Summary.............................................................................................................................................102
Chapter 4: Installing Software.....................................................................................................................103
Overview.............................................................................................................................................103
What Is RPM?.....................................................................................................................................103
The RPM Package Management (GUI) Tool...............................................................................104
The RPM Command Line Tool..........................................................................................................110
Querying Packages.......................................................................................................................110
RPM Package Security.................................................................................................................113
Installing Packages.......................................................................................................................115
Removing Packages.....................................................................................................................117
Upgrading Packages.....................................................................................................................118
Verifying Package Integrity.........................................................................................................119
Package Installation in TAR Format...................................................................................................119
Summary.............................................................................................................................................121
Chapter 5: Everyday Applications...............................................................................................................123
Overview.............................................................................................................................................123
Office Applications.............................................................................................................................123
Red Hat Linux and Office Applications.......................................................................................124
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Table of Contents
Chapter 5: Everyday Applications
Installing Office Applications......................................................................................................125
Starting an OpenOffice Application.............................................................................................126
Common Functionality.................................................................................................................127
Conversion Quality and Considerations.......................................................................................133
Using OpenWriter for Word Processing......................................................................................133
Using OpenCalc for Spreadsheets................................................................................................134
Using OpenImpress for Presentations..........................................................................................135
Internet Applications...........................................................................................................................136
The Mozilla Web Browser...........................................................................................................136
The GAIM Instant Messenger Application..................................................................................138
Personal Information Management.....................................................................................................140
Installing Evolution......................................................................................................................140
Setting up Evolution.....................................................................................................................140
Using Evolution............................................................................................................................141
Importing E−mail from other Systems.........................................................................................146
Multimedia Applications....................................................................................................................147
Audio Applications.......................................................................................................................148
Graphics Applications..................................................................................................................154
System Applications...........................................................................................................................156
A Simple Text Editor...................................................................................................................156
A File Management Application..................................................................................................157
A File Compression and Archiving Application..........................................................................158
Emulators......................................................................................................................................159
Summary.............................................................................................................................................160
Chapter 6: The Shell......................................................................................................................................161
Overview.............................................................................................................................................161
The Shell as a Command Line Interface.............................................................................................161
Different Types of Shell...............................................................................................................162
Built−in Programs and External Programs.........................................................................................163
Some Common Shell Commands.......................................................................................................164
File System Commands................................................................................................................164
Process Management Commands.................................................................................................168
Administrative Commands...........................................................................................................170
Special Keys and Shortcuts.................................................................................................................172
Control Keystrokes.......................................................................................................................172
Cursor Keys..................................................................................................................................173
Auto−completion..........................................................................................................................175
Command Line Syntax.......................................................................................................................176
File Globbing................................................................................................................................176
Aliases..........................................................................................................................................178
Environment Variables.................................................................................................................179
I/O Redirection.............................................................................................................................180
Configuring the Shell..........................................................................................................................182
Managing Tasks..................................................................................................................................183
Processes......................................................................................................................................184
Job Control...................................................................................................................................184
Scheduling Tasks..........................................................................................................................185
Shell Scripting.....................................................................................................................................186
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Table of Contents
Chapter 6: The Shell
Variables.......................................................................................................................................187
Literal Usage of Special Characters.............................................................................................187
Conditional Constructs.................................................................................................................188
Loops............................................................................................................................................190
Summary.............................................................................................................................................191
Chapter 7: The File System...........................................................................................................................192
Overview.............................................................................................................................................192
What Is the File System?....................................................................................................................192
The Anatomy of a File..................................................................................................................192
File Search Utilities............................................................................................................................204
Searching with the locate Command............................................................................................204
Searching with the find Command...............................................................................................206
Searching with the GNOME Search Tool....................................................................................208
Text Searches...............................................................................................................................208
Navigating the File System.................................................................................................................210
Managing Drives and Partitions..........................................................................................................215
Mounting Drives...........................................................................................................................216
Partitions.......................................................................................................................................218
Adding a New Hard Disk.............................................................................................................222
File System Maintenance....................................................................................................................224
Precautions...................................................................................................................................224
Running fsck.................................................................................................................................225
Tuning the File System.................................................................................................................225
Summary.............................................................................................................................................226
Chapter 8: Managing Your User Accounts.................................................................................................227
Overview.............................................................................................................................................227
The Purpose of Different User Accounts............................................................................................228
Superusers and Normal Users......................................................................................................228
The Red Hat User Manager................................................................................................................229
How Linux Stores User Account Information....................................................................................234
User Accounts and their Properties (the /etc/passwd File)...........................................................235
User Account Passwords (the /etc/shadow File)..........................................................................237
Groups (the /etc/group File).........................................................................................................239
Advanced User Account Management...............................................................................................240
Some Useful Command Line Tools.............................................................................................240
Adding Users at the Command Line............................................................................................241
Modifying One's Own User Account...........................................................................................244
Deleting User Accounts................................................................................................................248
Advanced Group Management...........................................................................................................248
Users, Groups, and File System Permissions.....................................................................................250
First Scenario: Private Files.........................................................................................................251
Second Scenario: Public Read−only Files...................................................................................251
Third Scenario: Restricted Read−Only........................................................................................252
Fourth Scenario: Restricted Write................................................................................................253
Fifth Scenario: Restricted Write, Public Read.............................................................................255
Sixth Scenario: Restricted Write, Restricted Read.......................................................................255
When root Is Not Necessary...............................................................................................................256
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Table of Contents
Chapter 8: Managing Your User Accounts
Mounting Devices........................................................................................................................257
Using the su Command................................................................................................................259
Compiling, Installing, and Running Software..............................................................................261
Who Is Logged In?..............................................................................................................................262
Summary.............................................................................................................................................263
Chapter 9: Building Networks......................................................................................................................265
Overview.............................................................................................................................................265
Networking.........................................................................................................................................266
Red Hat Linux and Networking...................................................................................................266
Assumptions for Network Setup..................................................................................................267
Setting up a Web Server.....................................................................................................................270
The Apache Web Server...............................................................................................................271
Setting up an FTP Server....................................................................................................................277
FTP Servers in the Red Hat Linux Distribution...........................................................................278
Installing the vsftpd FTP Server...................................................................................................279
Using Your FTP Server................................................................................................................280
Setting up a Print Server.....................................................................................................................286
Print Servers on Redhat Linux 9..................................................................................................286
Setting up a File Server.......................................................................................................................291
An Overview of Samba................................................................................................................292
Samba Configuration with SWAT...............................................................................................295
Setting up a Mail Server.....................................................................................................................304
What Is a Mail Server?.................................................................................................................305
E−mail Application Types...........................................................................................................305
A Simple Example Using Sendmail.............................................................................................307
Setting up a DHCP Server..................................................................................................................312
How Does DHCP Work?.............................................................................................................312
The Benefits of DHCP.................................................................................................................313
Summary.............................................................................................................................................319
Chapter 10: Advanced System Administration..........................................................................................320
Overview.............................................................................................................................................320
System Configuration.........................................................................................................................320
Example: Finding the DNS Server...............................................................................................321
Configuration Files.......................................................................................................................321
Logging...............................................................................................................................................329
Viewing Logs...............................................................................................................................329
Searching Log Files......................................................................................................................331
Understanding the Logging Process.............................................................................................332
Backing Up and Archiving.................................................................................................................333
Backup Strategy...........................................................................................................................333
Applications and Tools for Archiving..........................................................................................335
Archiving with cpio......................................................................................................................337
Archiving with dump....................................................................................................................339
Building from Source..........................................................................................................................343
Installing Development Tools and Libraries................................................................................344
Building the Application..............................................................................................................344
Rebuilding the Linux Kernel..............................................................................................................348
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Table of Contents
Chapter 10: Advanced System Administration
Why Rebuild the Kernel?.............................................................................................................348
Initializing the Kernel...................................................................................................................349
A Small, Lean Kernel...................................................................................................................350
Summary.............................................................................................................................................358
Chapter 11: Managing Your System with Perl...........................................................................................359
Overview.............................................................................................................................................359
What Is Perl?.......................................................................................................................................360
Advantages...................................................................................................................................361
Disadvantages...............................................................................................................................362
Installation..........................................................................................................................................362
Installing Extensions....................................................................................................................363
Learning Perl.......................................................................................................................................365
How to Start..................................................................................................................................365
Application 1: Who Can Get In?..................................................................................................366
Who Can Get In? Take II.............................................................................................................369
Application 2: Send a Quick E−Mail...........................................................................................370
Application 3: What Is My System Load?...................................................................................376
Application 4: Disk Usage Monitor.............................................................................................386
And Finally.........................................................................................................................................393
Summary.............................................................................................................................................394
Chapter 12: Security......................................................................................................................................395
What Is Meant by Computer Security?...............................................................................................395
Identifying What Is Valuable.......................................................................................................395
Potential Threats...........................................................................................................................396
Countering the Threats........................................................................................................................397
Hardware.............................................................................................................................................397
Physical Security of the Hardware...............................................................................................397
Hardware Failure..........................................................................................................................398
Local Security.....................................................................................................................................399
(Mis)using the root Account.........................................................................................................399
Passwords.....................................................................................................................................399
Keeping Software Up to Date.............................................................................................................405
Registering for Red Hat Network.................................................................................................405
Monitoring Security............................................................................................................................406
System Logs.................................................................................................................................406
System Integrity...........................................................................................................................409
Network Security................................................................................................................................414
Network Services.........................................................................................................................415
Firewalls.......................................................................................................................................425
Security Awareness......................................................................................................................431
Where to find out more.......................................................................................................................432
Summary.............................................................................................................................................432
Chapter 13: Where to Now?.........................................................................................................................434
Overview.............................................................................................................................................434
Online Resources and Licensing Schemes.........................................................................................434
Software Resources......................................................................................................................434
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Table of Contents
Chapter 13: Where to Now?
Documentation Resources............................................................................................................435
Open Source Licenses..................................................................................................................435
System Administration Applications..................................................................................................437
The SysAdmin Application..........................................................................................................437
The GNOME Workstation Command Center..............................................................................438
Webmin........................................................................................................................................438
RT: The Request Tracker.............................................................................................................440
Development Applications..................................................................................................................440
jEdit..............................................................................................................................................440
Developing C/C++ Applications..................................................................................................441
Developing Python Applications..................................................................................................443
PHP: Hypertext Preprocessor.......................................................................................................444
MySQL Database Engine.............................................................................................................446
Summary.............................................................................................................................................447
List of "Try it Outs" and "How it Works"..................................................................................................449
Chapter 3: Connecting to the Internet.................................................................................................449
Chapter 4: Installing Software............................................................................................................449
Chapter 6: The Shell...........................................................................................................................449
Chapter 7: The File System................................................................................................................449
Chapter 8: Managing Your User Accounts.........................................................................................449
Chapter 9: Building Networks............................................................................................................450
Chapter 10: Advanced System Administration...................................................................................450
Chapter 12: Security...........................................................................................................................450
vii
Beginning Red Hat Linux 9
Sandip Bhattacharya,
Pancrazio De Mauro,
Shishir Gundavaram,
Mark Mamone,
Kalip Sharma,
Deepak Thomas,
Simon Whiting
Published by
Wiley Publishing, Inc.
10475 Crosspoint Boulevard
Indianapolis, IN 46256
www.wiley.com
Copyright © 2003 by Wiley Publishing, Inc., Indianapolis, Indiana
Published simultaneously in Canada
Library of Congress Control Number: 2003107085
ISBN: 0−7645−4378−4
Manufactured in the United States of America
10 9 8 7 6 5 4 3 2 1
1B/RV/QX/QT/IN
No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by
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Beginning Red Hat Linux 9
The advice and strategies contained herein may not be suitable for your situation. You should consult with a
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About the Authors
Sandip Bhattacharya is an independent technology consultant specializing in Open Source technologies. He
is a Red Hat Certified Engineer (RHCE) and besides holding degrees in engineering and management is the
author of a number of books and articles on Open Source software. He currently runs Puroga Technologies, a
small startup with a focus on helping businesses use the Open Source revolution to their advantage. He can be
contacted at <[email protected]>. Sandip is an active participant in various Open Source communities in
India, especially his local LUG, the Indian Linux Users Group, Delhi (ILUGD).
Pancrazio 'Ezio' de Mauro has been using Red Hat Linux since 1996. He is a Linux consultant specializing
in system integration, mobile technologies, and training. He actively supports and advocates the use of free
software. Ezio spends most of his free time traveling and backpacking. He welcomes comments and questions
at his e−mail address, <[email protected]>.
Shishir Gundavaram is the Chief Technology Officer for MechanicNet Group, a company that specializes in
providing CRM services for the automotive repair and maintenance industry. When he is not dealing with
auto mechanics and broken−down cars, Shishir consults for a number of companies, designing architecture
and providing technical expertise. He has more than a decade of experience in various aspects of software
development and is considered a foremost expert in wireless applications, distributed systems, electronic
commerce, and web backend architecture. He is also the author of various articles and books, including
Professional Perl Development, CGI Programming on the World Wide Web, and Scripting Languages:
Automating the Web, and he is regularly invited to speak at technical conferences around the world.
Mark Mamone, a Solutions Specialist working for Syntegra Ltd in the UK, has 16 years of experience in the
IT industry ranging from Assembler and MS−DOS and now specializing in the development of enterprise and
mobile systems using a variety of technologies, including Microsoft .NET, Java, and Linux. I would like to
thank my parents for the Commodore Vic−20, without which my life would have never taken this path. I
would like to thank my children − Tanya, James, and Cameron − whose love is my foundation and, most
important, my girlfriend, Rachel, whose support, love, and never−ending drive enabled me to complete this
book!
Kapil Sharma, an Internet security and Unix consultant, has been working on various Unix systems and
Internet security technologies for more than five years. He has deployed many Unix, high availability,
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