www.allitebooks.com Unix® for Programmers and Users Third Edition Graham Glass and King Ables Pearson Education, Inc. Upper Saddle River, New Jersey 07458 www.allitebooks.com Library of Congress Cataloging-in-Publication Data CIP data on file Vice President and Editorial Director, ECS: Marcia Horton Executive Editor: Petra Recter Editorial Assistant: Renee Makras Vice President and Director of Production and Manufacturing, ESM: David W. Riccardi Executive Managing Editor: Vince O’Brien Assistant Managing Editor: Camille Trentacoste Production Editor: Lakshmi Balasubramanian Director of Creative Services: Paul Belfanti Creative Director: Carole Anson Art Director: Jayne Conte Cover Designer: Bruce Kenselaar Art Editor: Gregory Dulles Manufacturing Manager: Trudy Pisciotti Manufacturing Buyer: Lisa McDowell Marketing Manager: Pamela Shaffer Marketing Assistant: Barrie Reinhold © 2003 Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 All rights reserved. No part of this book may be reproduced, in any form or by any other means, without permission in writing from the publisher. The author and publisher of this book have used their best efforts in preparing this book. These efforts include the development, research, and testing of the theories and programs to determine their effectiveness. The author and publisher make no warranty of any kind, expressed or implied, with regard to these programs or the documentation contained in this book. The author and publisher shall not be liable in any event for incidental or consequential damages in connection with, or arising out of, the furnishing, performance, or use of these programs. Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 ISBN 0-13-046553-4 Pearson Education Ltd., London Pearson Education Australia Pty. Ltd., Sydney Pearson Education Singapore, Pte. Ltd. Pearson Education North Asia Ltd., Hong Kong Pearson Education Canada, Inc., Toronto Pearson Educación de Mexico, S.A. de C.