Compaq Fortran
User Manual for
Tru64 UNIX and Linux Alpha Systems

Chapter 7
7	Compaq Fortran Input/Output (I/O)
7.1	Logical I/O Units
7.2	Types of I/O Statements
7.3	Forms of I/O Statements
7.4	Types of Files and File Characteristics
7.4.1	File Organizations
7.4.2	Internal Files and Scratch Files
7.4.3	Record Types, Record Overhead, and Maximum Record Length
7.4.3.1	Portability Considerations of Record Types
7.4.3.2	Record Overhead
7.4.3.3	Maximum Record Length
7.4.4	Other File Characteristics
7.5	File Operations: OPEN, INQUIRE, CLOSE Statements
7.5.1	Opening Files: The OPEN Statement
7.5.1.1	Using Preconnected Standard I/O Files
7.5.1.2	OPEN Statement Specifiers
7.5.1.3	Methods to Specify the Unit, File Name, and Directory
7.5.1.4	Accessing Files: Implied and Explicit File and Pathnames
7.5.1.5	How Compaq Fortran Applies a Default Pathname and File Name
7.5.1.6	Coding File Locations in an OPEN Statement
7.5.1.7	Using Environment Variables
7.5.2	Obtaining File Information: The INQUIRE Statement
7.5.2.1	Inquiry by Unit
7.5.2.2	Inquiry by File Name
7.5.2.3	Inquiry by Output Item List
7.5.3	Closing a File: The CLOSE Statement
7.6	Record Operations
7.6.1	Record I/O Statement Specifiers
7.6.2	Record Access Modes and File Sharing
7.6.2.1	Sequential Access
7.6.2.2	Direct Access
7.6.2.3	Limitations of Record Access by File Organization and Record Type
7.6.2.4	File Sharing
7.6.3	Specifying the Initial Record Position
7.6.4	Advancing and Nonadvancing Record I/O
7.6.5	Record Transfer
7.6.5.1	Input Record Transfer
7.6.5.2	Output Record Transfer
7.7	User-Supplied OPEN Procedures: the USEROPEN Specifier
7.7.1	Restrictions of Called USEROPEN Functions
7.7.2	Example USEROPEN Program and Function
7.8	Format of Compaq Fortran Record Types
7.8.1	Fixed-Length Records
7.8.2	Variable-Length Records
7.8.3	Segmented Records
7.8.4	Stream File Data
7.8.5	Stream_CR and Stream_LF Records
Chapter 8
8	Run-Time Errors and Signals
8.1	Compaq Fortran Run-Time Library Default Error Processing
8.1.1	Run-Time Message Format
8.1.2	Message Catalog Location
8.1.3	Values Returned to the Shell at Program Termination
8.1.4	Forcing a Core Dump for Severe Errors
8.2	Handling Errors
8.2.1	Using the END, EOR, and ERR Branch Specifiers
8.2.2	Using the IOSTAT Specifier
8.2.3	Using the 3f Library Routines to Return Operating System Errors
8.3	Signal Handling
8.4	List of Run-Time Messages
Chapter 9
9	Data Types and Representation
9.1	Summary of Data Types and Characteristics
9.2	Integer Data Representations
9.2.1	Integer Declarations and f90/fort Compiler Options
9.2.2	INTEGER (KIND=1) or INTEGER*1 Representation
9.2.3	INTEGER (KIND=2) or INTEGER*2 Representation
9.2.4	INTEGER (KIND=4) or INTEGER*4 Representation
9.2.5	INTEGER (KIND=8) or INTEGER*8 Representation
9.3	Logical Data Representations
9.4	Native IEEE Floating-Point Representations and Exceptional Values
9.4.1	REAL and COMPLEX Declarations and f90/fort Compiler Options
9.4.2	REAL (KIND=4) or REAL*4 Representation
9.4.3	REAL (KIND=8) or REAL*8 Representation
9.4.4	REAL (KIND=16) or REAL*16 Representation
9.4.5	COMPLEX (KIND=4) or COMPLEX*8 Representation
9.4.6	COMPLEX (KIND=8) or COMPLEX*16 Representation
9.4.7	COMPLEX (KIND=16) or COMPLEX*32 Representation
9.4.8	Exceptional Floating-Point Representations
9.5	Character Representation
9.6	Hollerith Representation
Chapter 10
10	Converting Unformatted Numeric Data
10.1	Endian Order of Numeric Formats
10.2	Native and Supported Nonnative Numeric Formats
10.3	Limitations of Numeric Conversion
10.4	Methods of Specifying the Unformatted Numeric Format
10.4.1	Environment Variable FORT_CONVERTn Method
10.4.2	Environment Variable FORT_CONVERT.ext Method
10.4.3	OPEN Statement CONVERT='keyword' Method
10.4.4	OPTIONS Statement /CONVERT=keyword Method
10.4.5	f90 Command -convert keyword Option Method
10.4.6	Additional Notes on Nonnative Data
Chapter 11
11	Procedure Data Interfaces and Mixed Language Programming
11.1	Compaq Fortran Procedures and Argument Passing
11.1.1	Explicit and Implicit Interfaces
11.1.2	Types of Compaq Fortran Subprograms
11.1.3	Using Procedure Interface Blocks
11.1.4	Passing Arguments and Function Return Values
11.1.5	Passing Arrays as Arguments
11.1.6	Passing Pointers as Arguments
11.1.7	Compaq Fortran Array Descriptor Format
11.1.8	Argument-Passing Mechanisms and Built-In Functions
11.1.8.1	Passing Addresses --- %LOC Function
11.1.8.2	Passing Arguments by Immediate Value --- %VAL Function
11.1.8.3	Passing Arguments by Reference --- %REF Function
11.1.8.4	Examples of Argument Passing Built-in Functions
11.2	Using the cDEC$ ALIAS and cDEC$ ATTRIBUTES Directives
11.2.1	The cDEC$ ALIAS directive
11.2.2	The cDEC$ ATTRIBUTES Directive
11.2.2.1	C Property
11.2.2.2	ALIAS Property
11.2.2.3	REFERENCE and VALUE Properties
11.2.2.4	EXTERN and VARYING Properties
11.3	Calling Between Compaq Fortran 77 and Compaq Fortran
11.3.1	Argument Passing and Function Return Values
11.3.2	Using Data Items in Common Blocks
11.3.3	I/O to the Same Unit Number
11.4	Calling Between Compaq Fortran and C
11.4.1	Compiling and Linking Files
11.4.2	Procedures and External Names
11.4.3	Invoking a C Function from Compaq Fortran
11.4.4	Invoking a Compaq Fortran Function or Subroutine from C
11.4.5	Equivalent Data Types for Function Return Values
11.4.6	Argument Association and Equivalent Data Types
11.4.6.1	Compaq Fortran Intrinsic Data Types
11.4.6.2	Equivalent Compaq Fortran and C Data Types
11.4.7	Example of Passing Integer Data to C Functions
11.4.8	Example of Passing Character Data Between Compaq Fortran and C
11.4.9	Example of Passing Complex Data to C Functions
11.4.10	Handling User-Defined Structures
11.4.11	Handling Scalar Pointer Data
11.4.12	Handling Arrays
11.4.13	Handling Common Blocks of Data
11.5	Calling Between Parallel HPF and Non-Parallel HPF Code