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Books: A User's Report

Elizabeth Zinkann

Linux applications continue to become more sophisticated and popular. They are as diverse as the community who utilizes them. Whether you prefer Applixware, Star Office, Word Perfect, GNUCash, PHP, mySQL, or the Gimp (to name a very few of the available applications), the Linux operating system offers a variety of tools and utilities. Two applications (or at least some documentation about them) are highlighted in this month's column. I also included a book about firewalls and security, and a visual guide to Linux. Specifically, this column includes reviews of: Gimp Pocket Reference by Sven Neumann, translated by Sven Riedel (O'Reilly & Associates, Inc.); Building Linux and OpenBSD Firewalls by Wes Sonnenreich and Tom Yates (John Wiley & Sons, Inc.); Linux Music & Sound by Dave Phillips (Linux Journal Press, No Starch Press); and Master Red Hat Visually by Michael Bellomo (maranGraphics/IDG Books).

Gimp Pocket Reference
Sven Neumann
Translated by Sven Riedel
O'Reilly & Associates, Inc.
ISBN 1-56592-731-1
97 Pages

Many administrators find themselves suddenly thrust into the world of graphics and Web design. The journey from the shell prompt to creating graphics and user interfaces can cause culture shock. A colleague recently admitted that opening the Gimp (GNU Image Manipulation Program) confused him. He much preferred recompiling the kernel or setting up a network to resizing and optimizing images, with or without magic wands. The set of icons that greet the Gimp user are relatively straightforward once you know their functions and capabilities. Several excellent references are available for the Gimp user, including: The Artist's Guide to the Gimp by Michael J. Hammel (a personal favorite, published by SSC, ISBN 1-57831-011-3); GIMP: The Official Handbook by Olaf S. and Karin Kylander (Coriolis Open Press, ISBN 1-57610-520-2); Grokking the GIMP by Carey Bunks (New Riders, ISBN 0-7357-0924-6); and Guerrilla Guide to Great Graphics with The GIMP by David D. Busch (Prima Tech, ISBN 0-7615-2407-X). These books describe what the GIMP can do, the respective procedures, and illustrate the results of the individual tools and filters.

The Gimp Pocket Reference discusses the essential features of version 1.2 and demonstrates the power and potential of its tools, filters, plug-ins, and preferences. Neumann begins by describing the toolbox, which is the Gimp's beginning work screen, and its associated commands. Following the Introduction and The Toolbox, Neumann details Tools, The Image Window, Preferences, The rc-Files, Creating and Editing Keyboard Shortcuts, Color Models, Drawing and Layer Modes, and File Formats. Neumann defines the purposes of each tool or filter, any existing keyboard shortcuts, and options available to the user. For example, he presents the Smudge Tool entry as follows:

Smudge Tool (SHIFT + S)
Smudge simulates the smearing of wet paint. The brush picks up some of the color that it passes over and paints with it for a little while.

Determines how long the chosen color remains in the brush. [Page 26]

Neumann (with the aid of Riedel's translation) provides a superb and well-organized guide to the many facets of the Gimp. Whether you want to enhance an image, add artistic filters and effects, or create a completely new design, the Gimp can be a powerful and effective utility. The toolbox and its related functions allow the user to implement both still and animated results. The Gimp Pocket Reference gives the user the key to the toolbox and is a superior resource either as an independent reference or as a complement to another text.

Building Linux and OpenBSD Firewalls
Wes Sonnenreich and Tom Yates
John Wiley & Sons, Inc.
ISBN 0-471-35366-3
362 Pages
Companion Web Site:

A general definition of a firewall describes its use as a barrier to prevent the spread of a fire within a building. The parallel computer meaning reflects only a slight change -- a computer firewall prevents easy access to data by an intruder, whether inside or outside the organization. Protecting information is often a double-edged sword; the process may implement security at the cost of user convenience and easy access (and vice versa). The experienced administrator maintains a delicate balance between a secure system and the user interface. In the introduction to Building Linux and OpenBSD Firewalls, Sonnenreich and Yates note that the value of building a firewall yourself adds an extra measure of security. You not only know how the firewall was installed, but also realize its strengths, weaknesses, and expected performance. The final and most important consideration for any security policy examines "What am I protecting and who am I protecting it from?" The answer to that query should determine the strength of your security policy. Sonnenreich and Yates address the issue of security and its implementation through three major sections.

Part I introduces the theories and concepts connected with network security via The ABCs of Network Security, Fundamental Internet Security Issues, and How Secure Should Your Network Be? The authors describe fundamental network security issues for different sizes and types of organizations, emphasize what utilities are needed (and which aren't), and present some general guidance principles. In Part II, the authors detail the firewall implementations for both operating systems. The first chapter examines the historical perspective of the operating system environments, describing what issues were involved and what resulted from the events. Chapter 5, Getting The Right Hardware, is a mini-guide to system components and assembly. (This can often be a more challenging task than it seems, depending on the availability of parts your supplier carries.) The following four chapters feature Installing Linux, Configuring the Firewall under Linux, Installing OpenBSD, and Configuring the Firewall under OpenBSD. The section's final chapter presents Tuning Your Firewall and examines security policies, masquerading, routing, and performance improvement. In the final section, Part III, Sonnenreich and Yates depict Intrusion Detection and Response, and Loose Notes, which includes References by Chapter, A Brief vi Tutorial, The Security Policy, Scripts, and Some Closing Thoughts.

Building Linux and OpenBSD Firewalls offers the systems administrator an extensive amount of practical advice as well as some historical perspectives and security concepts. Sonnenreich and Yates use Red Hat 6.0 and OpenBSD 2.5, adding that most of the Linux information is applicable for any Linux distribution and any differences between releases will be minimal. The authors present some of the best information through the Notes, Tips, and shaded sidebars, which appear throughout the text. They even address the Linux versus OpenBSD question in the Introduction:

Both the Linux community and the OpenBSD community understand that it's not about which open source system is better. It's really about choosing open source as a viable alternative in the first place. [page xvi]

This is an excellently written and organized examination of existing security perceptions and procedures. Sonnenreich and Yates emphasize that you cannot add secure safeguards like post-it notes. They must be carefully planned and cohesively integrated within the administration routine. Building Linux and OpenBSD Firewalls is a valuable and effective resource for every systems administrator and Internet Service Provider.

Linux Music & Sound
Dave Phillips
Linux Journal Press
No Starch Press
ISBN 1-886411-34-4
408 Pages
CDROM Included

The idea of using a computer to generate music is an intriguing thought. The controls not only can be graphically represented, but also can be precisely controlled. However, the documentation for using a Linux system for implementing a recording studio has (until now) been online. Finding the information and the programs simultaneously has presented a challenge. With the Linux Music & Sound book by Dave Phillips, discovering the software, its location, and how to implement it is now available in one book. Within this rather unassuming volume, the aspiring Linux musician can now discover the procedures, programs (or where to locate them), and configurations for MIDI, MP3, and sound synthesis in one place. The musician/author (or author/musician) maintains the "Sound & MIDI Software for Linux" Web site and is also experienced with answering queries and discovering the available software programs.

Phillips examines the implementations of sound and music through the following chapters: The World Of Linux Music & Sound; Basics of Digital Audio; Setting Up Your System; Mixing, Playing, And Recording; Soundfile Editors; Mod Files and Linux; The Linux MIDI Studio; Linux Does MP3; Multitrack Hard-Disk Recording and Mixing; Software Sound Synthesis; Realtime Software Synthesizers; Music Notation Programs; Network Audio Software; Linux and the Digital DJ; Linux Games; and Operating System Emulators. The Appendices contain an Afterword, Glossary, About the CD-ROM, a Bibliography, and an Index. In the first three chapters, Phillips discusses the sound installation and configuration within a Linux system. Throughout the following chapters, he explores the different aspects of the sound and music phenomena and also details the various programs that can be used for each specific topic. Most of the programs that he describes are included on the accompanying CDROM.

Linux Music & Sound demonstrates the many ways in which sound can be used on a Linux system. Phillips illustrates his musical expertise through the descriptions of the concepts, the inclusion of the specific programs with installation instructions and troubleshooting techniques, and the wide range of audio-specific applications. This is a superb book about a little-documented area of Linux applications. His patient and detailed answers and explanations on each topic make the topics easy to understand, even from an amateur standpoint. This is an excellent reference both for basic sound procedures and for programs currently available for the Linux musician.

Master Red Hat Visually
Michael Bellomo
maranGraphics/IDG Books
ISBN 0-7645-3436-X
560 Pages
Two CD-ROMs Included

The majority of readers learn most effectively through some type of visual representation or connotation. The adage claiming that a picture is worth a thousand words is more truth than cliché. Master Red Hat Visually by Michael Bellomo is an excellent example of visual information. This offering from maranGraphics and IDG books features an introduction to the Linux operating system, beginning administration, networking, security, and disaster recovery. Bellomo addresses the concepts through eight major sections and the Appendices, including: Getting Started; Using the Linux Environment Outside of the GUI; Starting Linux Administration; The Linux Network -- The World Beyond Your Computer; Sharing Files and Machines Over the Network; The Internet and Electronic Mail; Network Security; and Disaster Preparation and Recovery.

Each section contains three to five chapters with accompanying screen shots (there are more than 1200 throughout the book) to demonstrate how to complete various tasks. This format allows the reader to preview configuration changes, etc. and know exactly what to expect. The first three parts (Getting Started, Using the Linux Environment Outside of the GUI, and Starting Linux Administration) provide the reader with basic configuration and navigation information through: Getting Started with Linux Basics; Customizing Your Desktop Environment; Working with Linux Files; Linux Commands; and GNOME, Working with Linux Files Outside of GNOME; Useful Commands Outside the GNOME; The vi Editor; Customize the Non-GNOME Environment; The Root User; User and Group Account Management; Managing the File System; Managing Linux Programs; and Word Processing in Linux.

Following these chapters, the user has several choices, depending on his or her particular environment and preferences. Part IV discusses networking in Networking in the Linux GNOME Environment; Remotely Logging onto Other Machines; and Copying Files To and From Other Machines. The following section describes ways to share printers and files through Setting Up Network Printers; The Network File System; The Network Information System -- NIS and Samba NIS Client Configuration; and Setting Up Network Database Users. In Part VI, The Internet and Electronic Mail, Bellomo details Establishing Network Connectivity; Setting Up Your Netscape Browser; Installing and Configuring Apache; and Sending and Receiving Mail in the Linux Terminal. The Network Security section examines Your Security Scheme; Tracking Intruders and Users on Your System; and The Aftermath: What To Do. The concluding chapters concentrate on Disaster Preparation and Recovery, including: Backing Up Files; The Y2038K Bug; and Troubleshooting Common Linux Problems. The Appendixes contain A) Installing Linux, B) Linux Applications You Should Be Aware Of, C) Summary of vi Editor Commands, and D) Glossary of Linux Terms and Commands.

Bellomo provides a worthwhile and varied approach to learning Linux. Each topic features a textual description, a visual representation of the applicable screen shots, a step-by-step procedure, and a Tips section. The latter utilizes a question and answer format, highlighting some common problems and queries. A frequent complaint about visual books is that they present a lot of screen shots, but little description. Master Red Hat Visually presents a multi-faceted approach that employs a combination of text and screen shots; the author also details more of the intermediate topics than most beginning books. The result is an excellent beginning book with a good reference guide.

Elizabeth Zinkann has been involved in the UNIX and C environment for the past 15 years. She is currently a UNIX and C consultant, and one of her specialties is UNIX education. In addition to her computer science background, she also has a degree in English. Her writing has also appeared in Linux Magazine, Performance Computing, and Network Administrator. Elizabeth can be reached at: