FORTRAN Reference Manual

Contents

FORTRAN Reference Manual—528615-001

iii

4. Program Units (continued)

Recursion 4-10

Using Multiple Entry Points in Functions and Subroutines 4-10

Using Adjustable Dimensions for Arrays and String Variables 4-11

Assumed-Size Array Declarator 4-12

Adjustable Array Declarator 4-13

Assumed-Size Length Declarator 4-13

Using Common Blocks 4-14

The Block Data Subprogram 4-15

5. Introduction to File I/O in the HP NonStop Environment

FORTRAN I/O Statements 5-1

Records 5-2

FORTRAN Files 5-3

External and Internal Files 5-3

File Properties 5-4

Units 5-8

File Existence 5-9

Opening a File 5-9

Unit Existence 5-10

Unit Assignment 5-10

Unit Connection 5-13

Specifying File Attributes 5-13

File Characteristics 5-16

Unstructured Files 5-16

Structured Files 5-18

Operations on HP-defined Files 5-24

Control Specifiers in I/O Statements 5-24

I/O Lists 5-26

Using Implied DO Lists 5-27

Unformatted I/O 5-28

Formatted I/O 5-28

List-Directed I/O 5-28

I/O Performance 5-31

Sequential Block Buffering 5-31

Read-Through Locks 5-31