Document revision date: 30 March 2001
[Compaq] [Go to the documentation home page] [How to order documentation] [Help on this site] [How to contact us]
[OpenVMS documentation]
OpenVMS User's Manual

OpenVMS User's Manual

Order Number: AA--PV5JE--TK

April 2001

This manual describes how to use the Compaq OpenVMS operating system. The information contained in this manual is intended for all OpenVMS users and is applicable to all computers running the OpenVMS operating system.

Revision/Update Information: This manual supersedes the OpenVMS User's Manual, Version 7.2.

Software Version: OpenVMS Alpha Version 7.3
OpenVMS VAX Version 7.3

Compaq Computer Corporation Houston, Texas

© 2001 Compaq Computer Corporation

Compaq, VAX, VMS, and the Compaq logo Registered in U.S. Patent and Trademark Office.

OpenVMS is a trademark of Compaq Information Technologies Group, L.P. in the United States and other countries.

Microsoft, MS, and MS--DOS are registered trademarks of Microsoft Corporation.

Motif, OSF, OSF/1, and OSF/Motif are registered trademarks, and Open Software Foundation is a trademark of The Open Group.

All other product names mentioned herein may be trademarks of their respective companies.

Confidential computer software. Valid license from Compaq required for possession, use, or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license.

Compaq shall not be liable for technical or editorial errors or omissions contained herein. The information in this document is provided "as is" without warranty of any kind and is subject to change without notice. The warranties for Compaq products are set forth in the express limited warranty statements accompanying such products. Nothing herein should be construed as constituting an additional warranty.


The Compaq OpenVMS documentation set is available on CD-ROM.

Contents Index


Intended Audience

This manual is intended for all users of the Compaq OpenVMS operating system.

A system manager performs the administrative tasks that create and maintain an efficient computing environment. If you are a system manager or want to understand system management concepts and procedures, refer to the OpenVMS System Manager's Manual.

Document Structure

This manual contains 19 chapters, 4 appendixes, and a glossary. Each chapter describes concepts and procedures for performing computing tasks. Basic information is presented first within each chapter; more complex concepts and procedures are presented last.

Getting Started

Refer to the following chapters to help you get started using the OpenVMS operating system:

Communicating with Other Users

Refer to the following chapters to learn about communicating with other users:

Manipulating Text and Records

Refer to the following chapters to learn about text processing and record sorting:

Using Devices

Refer to the following chapter to learn about devices:

Logical Names and Symbols

Refer to the following chapters to learn about logical names and symbols:


Refer to the following chapters to learn about writing programs and using programming functions:

Managing Processes

Refer to the following chapter to learn about managing processes:

Ensuring Security

Refer to the following chapter to learn about security:

Reference Sections

The following information is provided for reference:

Related Documents

For additional information about OpenVMS products and services, access the following World Wide Web address: 

Reader's Comments

Compaq welcomes your comments on this manual. Please send comments to either of the following addresses:
Mail Compaq Computer Corporation
OSSG Documentation Group, ZKO3-4/U08
110 Spit Brook Rd.
Nashua, NH 03062-2698

How To Order Additional Documentation

Use the following World Wide Web address to order additional documentation: 

If you need help deciding which documentation best meets your needs, call 800-282-6672.


In this manual, any reference to OpenVMS is synonymous with Compaq OpenVMS.

VMScluster systems are now referred to as OpenVMS Cluster systems. Unless otherwise specified, references to OpenVMS Clusters or clusters in this document are synonymous with VMSclusters.

In this manual, every use of DECwindows and DECwindows Motif refers to DECwindows Motif for OpenVMS software.

The following conventions are also used in this manual:
Ctrl/ x A sequence such as Ctrl/ x indicates that you must hold down the key labeled Ctrl while you press another key or a pointing device button.
PF1 x A sequence such as PF1 x indicates that you must first press and release the key labeled PF1 and then press and release another key or a pointing device button.
[Return] In examples, a key name enclosed in a box indicates that you press a key on the keyboard. (In text, a key name is not enclosed in a box.)

In the HTML version of this document, this convention appears as brackets, rather than a box.

... A horizontal ellipsis in examples indicate one of the following possibilities:
  • Additional optional arguments in a statement have been omitted.
  • The preceding item or items can be repeated one or more times.
  • Additional parameters, values, or other information can be entered.
A vertical ellipsis indicate the omission of items from a code example or command format; the items are omitted because they are not important to the topic being discussed.
( ) In command format descriptions, parentheses indicate that you must enclose the options in parentheses if you choose more than one.
[ ] In command format descriptions, brackets indicate optional elements. You can choose one, none, or all of the options. (Brackets are not optional, however, in the syntax of a directory name in an OpenVMS file specification or in the syntax of a substring specification in an assignment statement.)
[|] In command format descriptions, vertical bars separating items inside brackets indicate that you choose one, none, or more than one of the options.
{ } In command format descriptions, braces indicate required elements; you must choose one of the options listed.
bold text This text style represents the introduction of a new term or the name of an argument, an attribute, or a reason.
italic text Italic text indicates important information, complete titles of manuals, or variables. Variables include information that varies in system output (Internal error number), in command lines (/PRODUCER= name), and in command parameters in text (where dd represents the predefined code for the device type).
UPPERCASE TEXT Uppercase text indicates a command, the name of a routine, the name of a file, or the abbreviation for a system privilege.
Monospace text 
Monospace text indicates code examples and interactive screen displays.

In the C programming language, monospace text identifies the following elements: keywords, the names of independently compiled external functions and files, syntax summaries, and references to variables or identifiers introduced in an example.

- A hyphen at the end of a command format description, command line, or code line indicates that the command or statement continues on the following line.
numbers All numbers in text are assumed to be decimal unless otherwise noted. Nondecimal radixes---binary, octal, or hexadecimal---are explicitly indicated.

Chapter 1
Introduction: OpenVMS Concepts and Definitions

OpenVMS is an interactive virtual memory operating system. While you are logged in to the computer, you and the system conduct a dialogue using the DIGITAL Command Language (DCL). You use DCL by entering commands, which the system reads and translates. You enter a command by typing it from your keyboard and pressing the Return key; the system responds by executing the command or by displaying an error message on the screen if it cannot interpret what you entered.

This chapter describes basic concepts about the OpenVMS operating system and its components. It includes introductory information about the following topics:

Differences in Your Local Environment

Note that this manual covers standard DCL commands only. System managers at your site may tailor your system to support the local environment. They might decide to:

For additional information about the commands discussed in this chapter, refer to:

For additional information about Extended File Specifications, refer to:

1.1 Logging In to the System

Logging in consists of gaining access to the system and identifying yourself as an authorized user. When you log in, the system creates an environment from which you can enter commands. This environment is called your process.

Chapter 2 describes how to log in to and out of the system.

To interact with the operating system, you must log in to a user account. An account is a name or number that identifies you to the system when you log in. That name or number tells the system where your files are stored and the type of access you have to other files.

Your system manager (or whoever authorizes system use at your installation) usually sets up accounts and grants privileges according to your needs. The type of access rights and privileges enabled for your account determine whether you have access to files, images, or utilities that might affect system performance or other users.

1.1.1 Access Requirements

To access your account, you need to enter your user name and password. Your system manager usually provides you with your user name and initial password. Your user name identifies you to the system and distinguishes you from other users. In many cases, a user name is your first or last name. Your password is for your protection. If you maintain its secrecy, other users cannot use system resources under your user name.

1.2 Networks

When computer systems are linked together, they form a network. Operating systems in an OpenVMS network are able to communicate with each other and share information and resources. Each system in a network is called a network node or host and is identified by a unique name or address. Host and node are used interchangeably, and mean a system connected to a network.

With OpenVMS, you have a choice of networking protocols. You can use the Compaq TCP/IP Services for OpenVMS product or Compaq's DECnet products within a single network, or you can have an environment where both products exist. Compaq's primary network strategy for OpenVMS is TCP/IP, the industry-standard network protocol suite.

1.2.1 Network Nodes

When you are logged in to a network node, you can communicate with other nodes in the network. The node at which you are logged in is called the local node; other nodes on the network are called remote nodes. If you have access to an account on a remote node, you can log in to that account from your local node and perform tasks on that node while remaining connected to your local node.

Chapter 2 describes how to log in to a remote node. Additional tasks you can perform on remote nodes are described in the appropriate chapters of this manual.

1.2.2 Executing Programs over Networks

Because of support provided by TCP/IP and DECnet software, programs can execute across the network as if they were executing locally. Because the network software is integrated within the operating system, it is easy to write programs that access remote files. To access a remote file in an application program, you need only include the name of the remote node and any required access control information in the file specification.

Task-to-task communications, a feature common to all TCP/IP or DECnet implementations, allows two application programs running on the same or different operating systems to communicate with each other regardless of the programming languages used. Examples of network applications are distributed processing applications, transaction processing applications, and applications providing connection to servers.


In the examples of remote operations in this manual, proxy accounts enable users to perform operations on remote systems. Proxy accounts are one way users can access remote systems. For additional ways to access remote systems, see the OpenVMS System Manager's Manual.

1.3 DIGITAL Command Language (DCL)

DIGITAL Command Language (DCL) is a set of English-like instructions that tell the operating system to perform specific operations. DCL provides you with over 200 commands and functions to use in communicating with the operating system to accomplish computing tasks.

1.3.1 Usage Modes

You can use DCL in the following two modes:

1.3.2 Types of DCL Commands

When you enter a DCL command, it is read and translated by the DCL interpreter. The way the command interpreter responds to a command is determined by the type of command entered. The three types of DCL commands are as follows:

Next Contents Index

  [Go to the documentation home page] [How to order documentation] [Help on this site] [How to contact us]  
  privacy and legal statement