Files - Introduction

Sections

Using the PREFIX Verb

Enabling, Disabling, and Changing Disks

Creating, Erasing, and Renaming Files

Opening and Closing Files

Accessing Files/Positioning the Pointer

Reading Data

Writing Data

Removing Records

Locking Records (EXTRACT)

Locking Files (LOCK)

Journaled Files and Transactions

BBj File Type Comparison

STRING Files

PROGRAM Files

SERIAL Files

INDEXED Files

SORT/DIRECT Files

MKEYED Files

MKEYED FIles - Using With String Templates

XKEYED Verb - Create XKEYED File

JKEYED Verb - Create Journaled File (Deprecated)

VKEYED Verb

ESQL Overview

Directory Files

C-ISAM Files

Directory and Disk Searching/Locating a File on Your System

The early implementations of Business BASIC used multiple disk drives. Each disk contained one directory. When a request was made to locate a file (using OPEN, RUN, LOAD, SAVE, ERASE, CALL, or ADDR) the filesystem automatically searched each disk starting with the first. Frequently, the program needed to know which disk the file was ultimately found on. PRO/5 must run in environments that are different from this concept. Some systems have multiple disk drives and multiple directories. Some systems hide the disk drives from the applications that see only multiple directories.

An OPEN command from PRO/5 will cause PRO/5 to search numerous directories until the named file or device is located. The disks searched are specified using the DISABLE/ENABLE and SETDRIVE commands.