Perl: the Complete Reference Second Edition This Page Intentionally Left Blank
Total Page：16
File Type：pdf, Size：1020Kb
Y L F M A E T Team-Fly® Perl: The Complete Reference Second Edition This page intentionally left blank. Perl: The Complete Reference Second Edition Martin C. Brown Osborne/McGraw-Hill New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto Copyright © 2001 by The McGraw-Hill Companies. All rights reserved. Manufactured in the United States of America. Except as per- mitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-219425-1 The material in this eBook also appears in the print version of this title: 0-07-212950-6. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trade- marked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringe- ment of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. For more information, please contact George Hoare, Special Sales, at [email protected] or (212) 904-4069. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensors reserve all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior con- sent. You may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to use the work may be terminated if you fail to comply with these terms. THE WORK IS PROVIDED “AS IS”. McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the con- tent of any information accessed through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability shall apply to any claim or cause what- soever whether such claim or cause arises in contract, tort or otherwise. DOI: 10.1036/0072194251 To Darcy and Leon, two little kittens who do try to help daddy with the typing, but usually just end up typing “jjskdjjvoookko000000000000000000000” About the Author Martin C. Brown is the author of six Perl books, including the first edition of Perl: The Complete Reference, Perl Programmer’s Reference, ActivePerl Developer’s Guide, and Debugging Perl. In addition to Perl, he has worked in Python, Java, Visual Basic, and other languages. A programmer for 15 years, he is the former IT director of a large advertising agency dealing with blue chip clients such as Hewlett Packard, Oracle, and Cable & Wireless. Copyright 2001 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. Contents at a Glance Part I Fundamentals 1 Perl Backgrounder . 3 2 Perl Overview . 17 3 Perl Parsing Rules . 37 4 Variables and Data . 73 5 Statements and Control Structures . 109 6 Subroutines, Packages, and Modules . 123 7 Working with Files . 161 8 Data Manipulation . 209 9 Errors and Trapping Them . 269 Part II Programming with Perl 10 Complex Data Structures . 287 11 System Information . 339 12 Networking . 361 vii Copyright 2001 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. viii Perl: The Complete Reference 13 Database Systems . 391 14 Interprocess Communication . 447 15 Other Execution Enhancements . 479 Part III Developing Applications 16 User Interface Tools . 513 17 Advanced User Interfaces . 529 18 Developing for the World Wide Web (WWW) . 575 19 Controlling Execution with Pragmas . 611 20 Extending and Embedding Perl . 641 Part IV Fine-Tuning Applications 21 Debugging and Tuning . 715 22 Perl Compiler . 773 23 Perl Documentation . 803 24 Cross-Platform Migration Traps . 825 25 Distributing Modules and Applications . 837 Part V Appendixes A Function Reference . 869 B Standard Perl Library . 993 C Resources . 1141 Index . 1153 Contents Acknowledgments . xxxiii Introduction . xxxv Part I Fundamentals 1 Perl Backgrounder . 3 Versions and Naming Conventions . 5 Perl, perl or PeRl? . 5 Life Before Perl 5.6 . 5 Perl History . 6 Main Perl Features . 7 Perl Is Free . 7 Perl Is Simple to Learn, Concise, and Easy to Read . 7 Perl Is Fast . 7 Perl Is Extensible . 7 Perl Has Flexible Data Types . 8 Perl Is Object Oriented . 8 Perl Is Collaborative . 8 Compiler or Interpreter . 8 ix Copyright 2001 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. x Perl: The Complete Reference Similar Programming Languages . 9 Unix Shells . 9 Tcl . 10 Python . 10 Java . 11 C/C++ . 12 awk/gawk . 12 Popular “Mythconceptions” . 13 It’s Only for the Web . 13 It’s Not Maintenance Friendly . 13 It’s Only for Hackers . 13 It’s a Scripting Language . 14 There’s No Support . 14 All Perl Programs Are Free . 14 There’s No Development Environment . 14 Perl Is a GNU Project . 15 Perl Is Difficult to Learn . 15 Perl Success Stories . 15 Y 2 Perl Overview . .L . 17 Installing and Using Perl . .F . 18 Writing a Perl Script . 19 Perl Under Unix . M. 19 Perl Under Windows . 22 Perl Under Mac OS . 28 A Perl Components . 32 Variables . .E . 32 OperatorsT . 34 Statements . 34 Subroutines (Functions) . 34 Modules . 35 Where Next? . 35 3 Perl Parsing Rules . 37 The Execution Process . 38 Syntax and Parsing Rules ..