The World of Scripting Languages (Worldwide Series in Computer Science)

507 Pages·2000·34.38 MB·English

by  David Barron

Bu Culinary chitectul'e
Computer Interest
Life Sciences B p
Accountlng '- Mathematics
Self-I mp rovement
Engineering
e Psychology
Interior Design )1 Chemistry
WILEY
JOSSEY-BASS
PFEIFFER
J.K.LASSER
CAPSTONE
WILEY-LISS
WILEY-VCH
WILEY-INTERSCIENCE
The World of Scripting
Languages
WORLDWIDE
SERIES IN
COMPUTER
SCIENCE
Series Editors Professor David Barron, Southampton University, UK
Professor Peter Wegner, Brown University, USA
The Worldwide series in Computer Science has been created to publish textbooks which
both address and anticipate the needs of an ever evolving curriculum thereby shaping its
future. It is for undergraduates majoring in Computer Science and practitioners
who need to reskill. Its philosophy derives from the conviction that the discipline of
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The World of Scripting
Lan uages
David W. Barron
University of Southampton, UK
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Library of Congress Cataloglng-In-Publicatlon Data
Barron, D. W. (David William), 1935-
The world of scripting languages / David W. Barron.
p. cm. (Worldwide series in computer science)
Includes bibliographical references and index.
ISBN 0~471-99886-9 (alk. paper)
1. Programming languages (Electronic computers) 2. CGI (Computer network
protocol) 3. World Wide Web. 1. Title. II. Series.
QA76.6-B3715 2000
99-089450
British Library Cataloguing in Publication Data
ISBN 0-471-99886-9
Typeset in 9/12 Garamond by Mayhew Typesetting, Rhayader, Powys
Printed and bound in Great Britain by Biddies Ltd, Guildford, Surrey
This book is printed on acid-free paper responsibly manufactured from sustainable forestry, in which
at least two trees are planted for each one used for paper production.
Contents
Preface .................................. . xi
Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. xiii
PART ONE THE BIG PICTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Introduction to and scripting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 and programs.. ............................... 3
1.2 Origins of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Scripting today. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ...... 5
1.4 Characteristics of scripting . . . . . . . .. ............. 5
1.5 Uses for scripting languages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.6 Web scripting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
1.7 Java............................................. 13
1.8 The universe of scripting . . . . . . . . . . . . . . . . . . . 13
PART TWO LANGUAGES..................................... 15
2 the done in Perl . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1 The Perl phenomenon. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 Introducing Perl. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 Names and values in Perl. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.4 Variables and ass;igrlm,ent. . . . . . . .. . ................... . 28
2.5 Scalar ext)ressi()ns 29
2.6 Control structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.7 Built-in functions ................................... . 36
2.8 Collections of data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.9 Working with arrays and lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.10 Working with hashes ................................ . 45
2.11 input and output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.12 Strings, patterns and regular expressions. . . . . . . . . . . . . . . . . . . . . 48
2.13 Subroutines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
2.14 Scripts with arguments . . .. .......................... . 61
2.15 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.16 Reference: operators and precedence . . . . . . . . . . . . . . . . . . . . . . . 63
Contents
3 Advanced Perl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64
3.1 Finer points of looping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64
3.2 Finer points of subroutines . . . . . . . . . . ................... , 65
3.3 Using pack and unpack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 68
3.4 Working with files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 69
3.5 Navigating the file system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 74
3.6 Typeglobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 76
3.7 eval............................................. 78
3.8 References......................................... 79
3.9 Data structures. . . . . . . .............................. , 86
3.10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 88
3.11 Libraries and modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 89
3.12 Objects........................................... 92
3.13 Objects and modules in action ........................... , 97
3.14 Tied variables ....................................... 100
3.15 Interfacing to the system ......................... 103
3.16 Creating 'Internet-aware' applications ....................... 109
3.17 'Dirty hands' Internet programming ......................... 112
3.18 Security issues ...................................... 116
4 l'cl .................................................. 118
4.1 The Tel phenomenon. ................................. 118
4.2 The Tel philosophy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
4.3 Tel structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
4.4 Tel syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
4.5 Understanding Tel: the parser . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
4.6 Variables and data in Tel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
4.7 Control flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
4.8 Data structures ...................................... 127
4.9 Simple input/output ................................... 130
4.10 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
4.11 Working with strings .................................. 135
4.12 Working with patterns ................................. 136
4.13 Working with files and pipes ............................. 140
4.14 Putting it all together: some code .................... 142
4.15 Reference material. ................................... 144
5 Advanced Tel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
5.1 The source, exec and uplevel commands ................. 148
5.2 Libraries and ................................. 149
5.3 Namespaces........................................ 152
5.4 Trapping errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 155
5 .5 Event-driven programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
5.6 Making applications 'Internet-aware' . . . . . . . . . . . . . . . . . . . . . . . . 159
5.7 'Nuts-and-bolts' Internet programming ....................... 161
Contents
5.8 <,:",,,,,,,,,,,,,,, issues: ... , ....... i..-"-. untmsted code. . . . . . . . . . . . . . . . . . . . .. 166
5.9 The C interface 169
5.10 The Java interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 173
6 Th .................................................. 176
6.1 Visual toolkits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 176
6.2 Fundamental concepts of Tk. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 177
6.3 Tk by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 182
6.4 Events and . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 198
6.5 Geometry managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 202
6.6 Perl-Tk............... ........................... 207
7 Visual Basic and VBA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 210
7.1 The Visual Basic family . . . . . . . . . . . . . . . . . . . . . . . . 210
7.2 Visual Basic: the core . . . . . . . . .. ................ 213
7.3 The Visual Basic way of objects . . . . . . . . . . .. ............. 230
7.4 Object models and type libraries . . . . . . . . . . . . . . . . . . . . . . . . .. 231
7.5 \Ylr,. .. lri1"ln with . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 232
7.6 ...................................... 241
7.7 Event-driven programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 245
7.8 Working with Visual Basic (the application). . . . . . . . . . . . . . . . . .. 247
7.9 Reference: operators and operator . . . . . . . . . . . . .. 255
8 Advanced Visual Basic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
8.1 Opveloninp Internet-aware applications ..................... . 257
8.2 COM objects. . . . . . . . . . . . . . . . . . .. . ................ . 262
8.3 The Visual Basic event model. . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
8.4 Class modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
8.5 276
8.6 ActiveX controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 285
8.7 Intc::tl<ilCirlg to the Windows API. . . . . . . . . . . . . . . . . . . . . . . . . .. 286
8.8 AC(:essiing external databases. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 288
PART THREE SCRIPTING WEB CLIENTS AND SERVERS . . . . . . . . . . . . . . . .. 293
9 295
9.1 What is ................................... 295
9.2 Object models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 296
9.3 philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 297
9.4 297
9.5 ............................ 298
9.6 objects. . . . . . . . .. ........................... 313
9.7 Advanced facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 322
9.8 JavaScript and Java. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 324
9.9 If}u''1~f"''rint operators and pn~Cedel[1Ce 325
Contents
10 VBScript .............................................. 326
10.1 What is VB Script? .................................... 326
10.2 The VBScript core language ............................. 327
10.3 Objects in VBScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
10.4 New features in VBScript 5 .............................. 338
11 Scripting Web clients and servers .............................. 344
11.1 Client-side Web scripting ............................... 344
11.2 Active Server Pages ................................... 362
12 Dynamic HTML and the DOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368
12.1 From HTML to Dynamic HTML ........................... 368
12.2 Dynamic HTML ..................................... 369
12.3 Document object models ............................... 369
12.4 The Netscape document object model ....................... 370
12.5 The Microsoft document object model. . . . . . . . . . . . . . . . . . . . . . . 375
12.6 The W3C document object model (DOM) .................... 380
12.7 The event model. .................................... 381
12.8 DHTML scriptlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
PART FOUR THE MICROSOFT SCRIPTING MODEL 395
13 Scripting Microsoft Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
13.1 VBA............................................. 397
13.2 Macros and macro languages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
13.3 WordBasic......................................... 399
13.4 The Office object models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
13.5 Programming the Word object model ....................... 404
13.6 Modifying Word's built-in dialogs. . . . . . . . . . . . . . . . . . . . . . . . . . 415
13.7 Events ........................................... 415
13.8 Automation: programming the Office suite .................... 418
13.9 Using the Windows API ................................ 422
13.10 Macro viruses ....................................... 423
14 The Microsoft Scripting Runtime Library. . . . . . . . . . . . . . . . . . . . . . . . . . 425
14.1 Scripting hosts, scripting and object libraries ............. 425
14.2 The Scripting Runtime Library ............................ 426
14.3 The Dictionary object. ................................. 426
14.4 The File System Object Model ............................ 428
14.5 Working with the FileSystemObject object .................... 430
14.6 The Drive object. .................................... 432
14.7 The File and Folder objects .............................. 433
14.8 Text I/O with the TextStream object ........................ 435
Contents
15 The Windows Script Host and the Script Control. . . . . . . . . . . . . . . . . . .. 440
15.1 What is the Windows Script Host? . . . . . . . . . . . . . . . . . . . . . . . .. 440
15.2 The Windows Script Host object model. . . . . . . . . . . . . . . . . . . . .. 441
15.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 444
15.4 The future of the Windows Script Host. . . . . . . . . . . . . . . . . . . . .. 446
15.5 The Script Control . . . . . . . . . . . . . . . . . .. ............... 446
PART FIVE AND FINALLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 449
16 Loose ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
16.1 Pre-history of sCripting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 451
16.2 Precursors of scripting. . . . . . . . . . . . . .. ............ 452
AWK ............................................ 459
16.4 REXX....................... .................... 464
17 t;;pUo~!ue ............................................. . 474
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 477
Index ................................................... 485
Scripting Program Index. . . . . . . . . . . . . . . . . . . . . . . . .. ............ 490