FORTRAN 77 Language Reference


This manual provides a reference to the Fortran 77 language accepted by the Sun(TM) FORTRAN 5.0 compiler f77.

Who Should Use This Book

This is a reference manual intended for programmers with a working knowledge of the Fortran language and some understanding of the Solaris(TM) operating environment and UNIX commands.

How This Book Is Organized

This book is organized into the following chapters and appendixes:

Chapter 1, "Elements of FORTRAN" introduces the basic parts of Sun FORTRAN 77, standards conformance, and elements of the language.

Chapter 2, "Data Types and Data Items" describes the data types and data structures in the language, including arrays, substrings, structures, and pointers.

Chapter 3, "Expressions" discusses FORTRAN expressions and how they are evaluated.

Chapter 4, "Statements" details the statements in the FORTRAN 77 language and the extensions recognized by the Sun compiler.

Chapter 5, "Input and Output" describes the general concepts of FORTRAN input/output and provides details on the different I/O operations.

Chapter 6, "Intrinsic Functions" tabulates and explains the intrinsic functions that are part of Sun FORTRAN 77, including VAX VMS extensions.

Appendix A, "ASCII Character Set" lists the standard ASCII character set.

Appendix B, "Sample Statements" shows samples of selected FORTRAN 77 statements for quick reference.

Appendix C, "Data Representations" introduces the way data is represented in FORTRAN.

Appendix D, "VMS Language Extensions" describes the VAX VMS language extensions provided in Sun FORTRAN 77.

Multi-Platform Release

Note -

The name of the latest Solaris operating environment release is Solaris 7 but some documentation and path or package path names may still use Solaris 2.7 or SunOS 5.7.

The SunTM WorkShopTM documentation applies to Solaris 2.5.1, Solaris 2.6, and Solaris 7 operating environments on:

Related Books

The following books augment this manual and provide essential information:

Other Programming Books

Other Sun WorkShop Books

Solaris Books

The following Solaris manuals and guides provide additional useful information:

Ordering Sun Documents

The SunDocsSM program provides more than 250 manuals from Sun Microsystems, Inc. If you live in the United States, Canada, Europe, or Japan, you can purchase documentation sets or individual manuals using this program.

For a list of documents and how to order them, see the catalog section of the SunExpressTM Internet site at

Accessing Sun Documents Online

Sun WorkShop documentation is available online from several sources:

Using the Web site

The Web site enables you to access Sun technical documentation online. You can browse the archive or search for a specific book title or subject. The URL is

Accessing AnswerBook2 Collections

The Sun WorkShop documentation is also available using AnswerBook2 software. To access the AnswerBook2 collections, your system administrator must have installed the AnswerBook2 documents during the installation process (if the documents are not installed, see your system administrator or Chapter 3 of Sun WorkShop Quick Install for installation instructions). For information about accessing AnswerBook2 documents, see Chapter 6 of Sun WorkShop Quick Install, Solaris installation documentation, or your system administrator.

Note -

To access AnswerBook2 documents, Solaris 2.5.1 users must first download AnswerBook2 documentation server software from a Sun Web page. For more information, see Chapter 6 of Sun WorkShop Quick Install.

Accessing HTML Documents

The following Sun Workshop documents are available online only in HTML format:

To access these HTML documents:

  1. Open the following file through your HTML browser:


    Replace install-directory with the name of the directory where your Sun WorkShop software is installed (the default is /opt).

    The browser displays an index of the HTML documents for the Sun WorkShop products that are installed.

  2. Open a document in the index by clicking the document's title.

Accessing Sun WorkShop Online Help and Release Notes

This release of Sun WorkShop includes an online help system as well as online manuals. To find out more see:

What Typographic Changes Mean

The following table describes the typographic changes used in this book.

Table P-1 Typographic Conventions

Typeface or Symbol 




The names of commands, files, and directories; on-screen computer output 

Edit your .login file.

Use ls -a to list all files.

machine_name% You have mail.



What you type, contrasted with on-screen computer output 

machine_name% su



Command-line placeholder: 

replace with a real name or value 

To delete a file, type rm filename.


Book titles, new words or terms, or words to be emphasized 

Read Chapter 6 in User's Guide. These are called class options.

You must be root to do this.

Shell Prompts in Command Examples

The following table shows the default system prompt and superuser prompt for the C shell, Bourne shell, and Korn shell.

Table P-2 Shell Prompts



C shell prompt 


C shell superuser prompt 


Bourne shell and Korn shell prompt 


Bourne shell and Korn shell superuser prompt