Linux command line & shell scripting bible

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www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page iii Linux ® Command Line and Shell Scripting Bible Richard Blum Wiley Publishing, Inc. www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page ii www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page i Linux ® Command Line and Shell Scripting Bible www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page ii www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page iii Linux ® Command Line and Shell Scripting Bible Richard Blum Wiley Publishing, Inc. www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page iv Linux ® Command Line and Shell Scripting Bible Published by Wiley Publishing, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2008 by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-0-470-25128-7 Manufactured in the United States of America 10987654321 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permit- ted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copy- right Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. 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Trademarks: Wiley, the Wiley logo, and related trade dress are trademarks or registered trademarks o f John Wiley & Sons, Inc. and/or its affiliates, in the United States and other countries, and may not be used without written permission. Linux is a registered trademark of Linus Torvald. 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. Wiley also publishes its books in a variety of electronic formats. Some content that appears i n print may notbeavailableinelectronicbooks. www.it-ebooks.info Blum ffirs.tex V2 - 04/04/2008 4:23pm Page v To all the people who’ve helped form my education. Parents, relatives, teachers, coworkers, and even anonymous posters on the Internet. Always be prepared to accept education from wherever you find it. Always continue to learn new things. ‘‘For the LORD gives wisdom, and from his mouth come knowledge and understanding.” Proverbs 2:6 (NIV) www.it-ebooks.info Blum fauth.tex V2 - 04/04/2008 4:42pm Page vi About the Author Richard Blum has worked in the IT industry for over 19 years as both a systems and network administrator. During this time he has administered Unix, Linux, Novell, and Microsoft servers, as well as helped design and maintain a 3500-user network utilizing Cisco switches and routers. He has used Linux servers and shell scripts to perform automated network monitoring, and has written shell scripts in just about every Unix shell environment. Rich has a bachelor of science degree in Electrical Engineering, and a master of science degree in Management, specializing in management information systems, from Purdue University. He is the author of several Linux books, including sendmail for Linux, Running qmail, Postfix, Open Source E-mail Security, Network Performance Open Source Toolkit,andProfessional Assembly Language Programming. H e’s also a coauthor of Professional Linux Programming and Linux For Dummies, 8th Edition. When he’s not being a computer nerd, Rich plays bass guitar for his church worship band and enjoys spending time with his wife, Barbara, and their two daughters, Katie Jane and Jessica. www.it-ebooks.info Blum fcredit.tex V2 - 04/04/2008 4:46pm Page vii Credits Acquisitions Editor Jenny Watson Senior Development Editor Tom Dinse Technical Editor John Kennedy Production Editor Angela Smith Copy Editor Foxxe Editorial Services Editorial Manager Mary Beth Wakefield Production Manager Tim Tate Vice President and Executive Group Publisher Richard Swadley Vice President and Executive Publisher Joseph B. Wikert Project Coordinator, Cover Lynsey Stanford Proofreader Word One New York Indexer Melanie Belkin www.it-ebooks.info [...]... Minimum Requirements Linux Command Line and Shell Scripting Bible looks at Linux from a generic point of view, so you’ll be able to follow along in the book using any Linux system you have available The bulk of the book references the bash shell, which is the default shell for most Linux systems Where to Go from Here Once you’ve completed Linux Command Line and Shell Scripting Bible, you’ll be well... with Linux Shells B efore you can dive into working with the Linux command line and shells, it’s a good idea to first understand what Linux is, where it came from, and how it works This chapter walks you through what Linux is, and explains where the shell and command line fit in the overall Linux picture IN THIS CHAPTER What Is Linux? Parts of the Linux kernel Exploring the Linux desktop What Is Linux? ... The Linux Command Line Chapter Chapter Chapter Chapter Chapter Chapter Chapter 1: 2: 3: 4: 5: 6: 7: Starting with Linux Shells .3 Getting to the Shell .25 Basic bash Shell Commands 59 More bash Shell Commands 91 Using Linux Environment Variables 123 Understanding Linux File Permissions .147 Working with Editors 171 Part II Shell. .. up-to-the-minute information about new advances in Linux xxx www.it-ebooks.info Page xxx Blum c01.tex V2 - 04/03/2008 2:57pm The Linux Command Line IN THIS PART Chapter 1 Starting with Linux Shells Chapter 2 Getting to the Shell Chapter 3 Basic bash Shell Commands Chapter 4 More bash Shell Commands Chapter 5 Using Linux Environment Variables Chapter 6 Understanding Linux File Permissions Chapter 7 Working with... to Linux Command Line and Shell Scripting Bible Like all books in the Bible series, you can expect to find both hands-on tutorials and real-world practical application information, as well as reference and background information that provides a context for what you are learning This book is a fairly comprehensive resource on the Linux command line and shell commands By the time you have completed Linux. .. xxvii Part I The Linux Command Line Chapter 1: Starting with Linux Shells 3 What Is Linux? 3 Looking into the Linux kernel 4 The GNU utilities 12 The Linux desktop environment 14 Linux Distributions 20 Core Linux distributions .21 Specialized Linux distributions 22 The Linux LiveCD ... 529 Part IV Alternative Linux Shells Chapter 20: The ash Shell 533 What Is the ash Shell? 533 The Original ash Shell 534 The Original ash command line parameters 534 The original ash built-in commands 536 The ash shell files 539 The dash Shell .540 The dash command line parameters 540 The dash... 587 The Korn Shell History .587 The Parts of the ksh93 Shell .588 Command line parameters 588 Default files 590 Environment variables .590 Built-in commands 597 Scripting in the ksh93 Shell 602 Mathematical operations 602 Structured commands .605 Command redirection .607 Discipline functions... time you have completed Linux Command Line and Shell Scripting Bible, you will be well prepared to write your own shell scripts that can automate practically any task on your Linux system Who Should Read This Book If you’re a system administrator in a Linux environment, you’ll benefit greatly by knowing how to write shell scripts The book doesn’t walk through setting up a Linux system, but once you have... administrative tasks That’s where shell scripting comes in, and that’s where this book will help you out This book will demonstrate how to automate any administrative task using shell scripts, from monitoring system statistics and data files to generating reports for your boss If you’re a home Linux enthusiast, you’ll also benefit from Linux Command Line and Shell Scripting Bible Nowadays it’s easy to get . xxvii Part I The Linux Command Line Chapter 1: Starting with Linux Shells 3 Chapter 2: Getting to the Shell 25 Chapter 3: Basic bash Shell Commands 59 Chapter. xxvii Part I The Linux Command Line Chapter1:StartingwithLinuxShells 3 What Is Linux? 3 Looking into the Linux kernel 4 The GNU utilities 12 The Linux desktop