Files and Devices Reference Guide Revision 1.0 Information in this document is subject to change without notice and does not represent a commitment on the part of Dynamic Concepts, Inc. (DCI). Every attempt was made to present this document in a complete and accurate form. DCI shall not be responsible for any damages (including, but not limited to consequential) caused by the use of or reliance upon the product(s) described herein. The software described in this document is furnished under a license agreement or nondisclosure agreement. The purchaser can use and/or copy the software only in accordance with the terms of the agreement. No part of this guide can be reproduced in any way, shape or form, for any purpose, without the express written consent of DCI. © Copyright 1998 Dynamic Concepts, Inc. (DCI). All rights reserved. UniBasic, BITS and Dynamic Windows™ are trademarks of Dynamic Concepts Inc. IRIS™ is a trademark of Point 4 Data Corporation. Table of Contents i CHAPTER 1 - INTRODUCTION............................................................................................................................................1 SYNTAX NOTATIONS.................................................................................................................................................................1 TYPOGRAPHICAL CONVENTIONS...............................................................................................................................................2 CHANNEL I/O...........................................................................................................................................................................3 I/O USING CHANNELS...............................................................................................................................................................3 THE UNIFICATION OF I/O VIA CHANNELS .................................................................................................................................3 RECORD LOCKING ....................................................................................................................................................................3 CHANNEL OPERATIONS, EXPRESSIONS AND PARAMETERS .......................................................................................................4 Channel Operations.............................................................................................................................................................4 Channel Expression - #chn.expr..........................................................................................................................................6 Arguments and Parameters .................................................................................................................................................6 CHANNEL FUNCTIONS AND OPERATIONS ..................................................................................................................................8 DL4 DRIVERS AND CLASSES .....................................................................................................................................................8 Benefits of Using dL4 Classes and Drivers........................................................................................................................10 MORE ON RECORD LOCKING ..................................................................................................................................................10 Operating System Support for Record Locking .................................................................................................................10 Implementations of Locking...............................................................................................................................................11 Reading through Record Locks..........................................................................................................................................11 DL4 CHARACTER SETS.......................................................................................................................................................13 INTRINSIC CHARACTER SETS ..................................................................................................................................................13 Unicode Character Set.......................................................................................................................................................14 SUPPORTED DRIVERS ........................................................................................................................................................15 DRIVER AUTO SELECTION MECHANISM..................................................................................................................................16 INTRODUCTION TO FILES.........................................................................................................................................................16 TEXT FILE CLASS....................................................................................................................................................................17 Special Options with Text Files .........................................................................................................................................18 Types of Text Files .............................................................................................................................................................18 Creating Text Files ............................................................................................................................................................19 Opening and Closing Text Files ........................................................................................................................................19 Positioning Within Text Files.............................................................................................................................................20 Record Locking with Text Files .........................................................................................................................................21 Reading and Writing Data with Text Files ........................................................................................................................21 Table of Text Driver Options Supported............................................................................................................................22 PIPE DRIVERS .........................................................................................................................................................................23 Types of Pipe Drivers ........................................................................................................................................................23 Creating a Pipe Driver ......................................................................................................................................................24 Opening and Closing Pipe Drivers....................................................................................................................................24 Locking with Pipe Drivers .................................................................................................................................................25 Reading and Writing with Pipe Drivers.............................................................................................................................25 PROFILE CLASS .......................................................................................................................................................................26 Types of Profile Drivers.....................................................................................................................................................26 Creating Profile Files ........................................................................................................................................................26 Opening and Closing Profile Files ....................................................................................................................................26 Positioning within Profile Files.........................................................................................................................................27 Record Locking with Profile Files .....................................................................................................................................27 Reading Profile Files.........................................................................................................................................................27 FORMATTED FILES CLASS.......................................................................................................................................................28 Special Options with Formatted Files ...............................................................................................................................28 Types of Formatted File Drivers........................................................................................................................................28 UniBasic Formatted File Driver .......................................................................................................................................................