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THIRD EDITION
THIRD
EDITION
A.S. PHILIPPAKIS
:
Arizona State University
LEONARD J. KAZMIER
Arizona State University
McGRAW-HILL BOOK COMPAN
New
York St. Louis San Francisco Auckland Bogota
Joha esburg ‘London Madrid MexicoM
em
Paris SaesPalic: Singapore
STRUCTURED COBOL
Copyright © 1986, 1981, 1977 by McGraw-Hill, Inc. All rights reserved. A majorrevision of COBOL
FOR BUSINESS APPLICATIONS, copyright © 1973 by McGraw-Hill, Inc. All rights reserved. Printed
in the United States of America. Except as permitted 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 data base orretrieval system, without the prior written permission of the publisher.
1234567890 WEBWEB 898765
ISBN 0-07-049809-1
This book was set in Times Roman by Monotype Composition Company, Inc.
The editors were Christina Mediate and Joseph F. Murphy;
the designer was Rafael Hernandez;
the production supervisor was Marietta Breitwieser.
The drawings were done by Accurate Art, Inc.
The cover photograph was taken by R. Wickham.
Webcrafters, Inc., was printer and binder.
See Acknowledgment on page xv. Copyrights included on this page by reference.
Library of Congress Cataloging-in-Publication Data
Philippakis, Andreas S.
Structured COBOL.
Includes index.
1. COBOL (Computer program language) 2. Business—
Data processing. |. Kazmier, Leonard J. Il. Title.
HF5548.5.C2P54 1986 005.133 85-17083
ISBN 0-07-049809-1
CONTENTS
PREFACE xiii
ACKNOWLEDGMENT
XV
OVERVIEW OF COBOL PROGRAMMING
=
Introduction
=
Levels of Computer Languages
Overall Structure of COBOL Programs
COBOL Characters and Words UTI
Data-Names
Constants
Sample COBOL Program
The COBOL Coding Form 14
An Outline for Your COBOL Programs 18
The Operating System and the Execution of COBOL Programs 18
Exercises 21
AN ELEMENTARY SET OF COBOL INSTRUCTIONS 23
Introduction 28
IDENTIFICATION DIVISION 23
ENVIRONMENT DIVISION 27
DATA DIVISION 28
The PICTURE Clause 31
PROCEDURE DIVISION 33
Input-Output Verbs 35
The MOVE Instruction 37
Arithmetic Verbs 38
Vil
viii CONTENTS
Conditional Expressions 40
Control Verbs 43
Debugging and Testing a Program 47
Exercises 50
PROGRAM STRUCTURE 54
Introduction 54
Characteristics of Good Programs 54
Flowcharting the Program Logic 56
Basic Forms of Structured Programming 60
Program Structure Charts
Pseudocode 66
An Illustration of Developing the Program Structure 67
Exercises 72
DATA DIVISION FEATURES 74
Introduction 74
Data Structure and Relationships 74
Record Layout 77
FILE SECTION 79
WORKING-STORAGE SECTION 80
The PICTURE Clause for Data Description 81
The PICTURE Clause for Data Editing 85
The BLANK WHEN ZERO Clause 92
Condition-Names 92
The VALUE Clause 94
Sample DATA DIVISION 94
Exercises 98
PROCEDURE DIVISION STATEMENTS 102
COBOL Language Formats 102
Arithmetic Verbs 104
The COMPUTE Verb Aid
File Input and Output 114
ACCEPT and DISPLAY Verbs 117
Data Transfer 121
The PERFORM Verb 124
The GO TO Verb 130
Sample Program 130
Exercises 134
CONDITIONS AND CONDITIONAL STATEMENTS 138
Introduction 138
Relation Conditions 138
Nested Conditions 141
Class Conditions 51
Using Conditionals to Check Input Data 153
Sign Conditions 156
Condition-Name Conditions 157
The SET Verb for Condition-Names 158
Complex Conditions 160
Exercises 161
CONTENTS ix
/
PROGRAM DESIGN 167
Introduction 167
Partitioning 167
The Black Box Concept for Cohesive Modules 168
Levels of Abstraction 171
Formatting Rules for Programs 175
Program Design for Control-Break Logic 179
Sample Program with Control Breaks 181
Exercises 187
ADDITIONAL LANGUAGE FEATURES 189
Introduction 189
IDENTIFICATION DIVISION 189
ENVIRONMENT DIVISION 189
The USAGE Clause 192
The SIGN Clause 194
The SYNCHRONIZED Clause 196
The JUSTIFIED RIGHT Clause 197
Qualification 198
Multiple Data Records 200
The REDEFINES Clause 202
The RENAMES Clause 203
Reference Modification 204
WRITE with the LINAGE Clause 206
The MOVE CORRESPONDING Option 208
The STRING and UNSTRING Verbs 209
The INSPECT Verb 214
The INITIALIZE Verb 217
The COPY Verb 218
Exercises 219
SEQUENTIAL FILE PROCESSING 225
File Organization 225
File Storage Devices 226
File Labels 230
COBOL Instructions for Sequential Files 232
The FILE-CONTROL Specification 232
The File-Description Entry 236
The OPEN and CLOSE Verbs 239
The READ, WRITE, and REWRITE Verbs 241
Sample Program to Create a Sequential File 242
Sequential File Updating 244
Sample Sequential File Update Program 246
Exercises 252
10
SORTING AND MERGING SEQUENTIAL FILES 257
COBOL Sort Feature 257
Sort Statement Formats 265
File Merging 268
Exercises 270
X CONTENTS
11 BASIC TABLE HANDLING 273
Introduction 273
Subscripting and the OCCURS Clause 273
Reading Values into a Table 276
Entering Constant Values into a Table 277
The OCCURS .. DEPENDING ON Option 279
.
The PERFORM Verb and Table Handling 281
Sample Forecasting Program 286
Sample Program with Graphic Output 288
Internal Sorting 290
Exercises 294
12
ADDITIONAL TABLE-HANDLING FEATURES 296
Two-Dimensional and Higher-Dimensional Tables 296
The PERFORM Verb and Table Handling 299
Sample Program with a Two-Dimensional Table 304
Sample Program with a Three-Dimensional Table 306
Table Searching with COBOL 309
COBOL Language Options in Table Searching 312
Sample Program with Indexing and Searching 315
Exercises 318
13
INDEXED SEQUENTIAL FILE PROCESSING 322
Introduction 322
Indexed Sequential File Organization 322
An Example of the Creation of an Indexed File 325
COBOL Language Instructions for Indexed Files 328
An Example of Processing an Indexed File 336
Exercises 340
14
RELATIVE FILE PROCESSING 342
Relative File Organization 342
The Division Remainder Method 344
Other Key-to-Address Transformation Methods 346
COBOL Statements for Relative Files 348
An Example of Creating a Relative File 352
An Example of Updating a Relative File 356
Exercises 362
15
SUBPROGRAMS AND NESTED PROGRAMS 364
Introduction 364
Calling and Called Programs 365
Sample Program with a Subprogram 369
COBOL Statements for Subprograms 372
Nested COBOL Programs 374
Exercises 379
APPENDIX A COBOL RESERVED WORDS 383
