COBOL Manual for TNS/E Programs (H06.03+)

Contents

HP COBOL Manual for TNS/E Programs—520347-003

xix

28. Disk Input and Output

Common Disk File Topics 28-1

Allocation 28-2

Partitioned Files 28-2

Purging Files or Their Data 28-2

Locking 28-3

Ownership and Security 28-3

Fixed-Length and Variable-Length Records 28-6

Exclusion Modes 28-6

Time Limits 28-7

Reading Files From Called Programs 28-7

Sharing Files Among HP COBOL Programs 28-8

Sharing Files Among Different-Language Modules 28-8

Modification 28-9

Maximum Number of Files 28-9

Types of HP Disk Files 28-9

Unstructured (Sequential) Files 28-9

Structured Files 28-10

Creating and Using HP COBOL Sequential Files 28-14

Entry-Sequenced Files 28-14

Unstructured Files 28-15

EDIT Files 28-16

Creating and Using HP COBOL Relative Files 28-16

Creating and Using HP COBOL Indexed Files 28-17

Creating and Using Queue Files 28-19

Creating a Queue File 28-19

Opening a Queue File 28-19

Reading a Queue File 28-20

Writing to a Queue File 28-20

Establishing Starting Points in Files 28-20

Key of Reference 28-21

Alternate Record Keys 28-22

Positioning 28-23

Repositioning to New Record With Same Alternate Key 28-26

Optimizing Disk File Processing 28-31

Unstructured Files 28-31

Structured Files 28-31

Files With Alternate Keys 28-35

Partitioned Files 28-36