Digital PDFs

AA-Z408A-TE

September 1984

68 pages

Original

7.2MB

Document:	VMS 4.0 VAX VMS Command Definition Utility Reference Manual
Order Number:	AA-Z408A-TE
Revision:
Pages:	68
Original Filename:	https://archive.org/download/stx_AA-Z408A-TE_VMS_4.0_VAX_VMS_Command_Definition_Utility_Reference_Manual_Sep84/AA-Z408A-TE_VMS_4.0_VAX_VMS_Command_Definition_Utility_Reference_Manual_Sep84.pdf

OCR Text

VAX/VMS
Command Definition
Utility Reference Manual
Order Number: AA-Z408A-TE

September 1984
This document describes the Command Definition Utility. This utility lets
you modify the DIGITAL command language (DCL) by adding commands
to your process command table or to a specified command table file.

Revision/Update Information:

This is a new manual.

Software Version:

VAX/VMS Version 4.0

digital equipment corporation
maynard, massachusetts

September 1984
The information in this document is subject to change without notice and should
not be construed as a commitment by Digital Equipment Corporation. Digital
Equipment Corporation assumes no responsibility for any errors that may appear
in this document.
The software described in this document is furnished under a license and may be
used or copied only in accordance with the terms of such license.
No responsibility is assumed for the use or reliability of software on equipment
that is not supplied by Digital Equipment Corporation or its affiliated companies.
Copyright ©1984 by Digital Equipment Corporation
All Rights Reserved.
Printed in U.S.A.
The postpaid READER'S COMMENTS form on the last page of this document
requests the user's critical evaluation to assist in preparing future documentation.
The following are trademarks of Digital Equipment Corporation:
DEC
DEC/CMS
DEC/MMS
DECnet
DECsystem-10
DECSYSTEM-20
DECUS
DECwriter

DIBOL
EduSystem
IAS
MASSBUS
PDP
PDT
RSTS
RSX

UNIBUS
VAX
VAXcluster
VMS
VT

2BEBDEB
ZK-2305

This document was prepared using an in-house documentation production system. All
page composition and make-up was performed by T^X, the typesetting system developed
by Donald E. Knuth at Stanford University. T^X is a registered trademark of the American
Mathematical Society.

Command Definition Contents
PREFACE

vii

NEW AND CHANGED FEATURES

FORMAT

CDU-1

COMMAND LANGUAGE DEFINITION STATEMENTS
AND CLAUSES
CDU-2
DESCRIPTION

CDU-3

COMMAND PROCESSING

CDU-4

1.1

Parts of a Command String

CDU-4

1.2

The System and Process Command Tables

CDU-5

USING THE CDU

CDU-5

CHOOSING A TABLE

CDU-5

3.1

Modifying Your Process Command Table

CDU-6

3.2

Adding a Command to the DCL Command Table

CDU-6

3.3

Creating an Object Module

CDU-6

WRITING A CFILE

CDU-7

4.1

Defining Command Verbs

CDU-8

4.2

Defining Syntax Changes With the DEFINE SYNTAX
Statement

CDU-9

4.3

4.4

Defining Values for Parameters, Qualifiers, and
Keywords

CDU-10

4.3.1

Built-In Types

CDU-10

4.3.2

User-Defined Keywords

CDU-11

Disallowing Combinations of Entities in Command
Definitions

CDU-11

4.4.1

Specifying Entities in an Expression

CDU-12

4.4.2

Operators

CDU-15
iii

Command Definition Contents

4.5

Providing Identifying Information for Object Modules

CDU-16

PROCESSING THE COMMAND DEFINITION FILE

CDU-17

5.1

Adding Command Definitions to a Command Table

CDU-17

5.2

Deleting Command Definitions

CDU-18

5.3

Creating an Object Module

CDU-18

5.4

Creating a New Command Table

CDU-18

USING COMMAND LANGUAGE ROUTINES

CDU-19

COMMAND DEFINITION FILE
STATEMENTS

CDU-20

DEFINE SYNTAX

CDU-21

DEFINE TYPE

CDU-29

DEFINE VERB

CDU-32

IDENT

CDU-38

MODULE

CDU-39

COMMAND QUALIFIERS

CDU-40

/DELETE

CDU-41

/LISTING

CDU-42

/OBJECT

CDU-43

/OUTPUT

CDU-44

/REPLACE

CDU-45

/TABLE

CDU-47

EXAMPLES
INDEX

CDU-49

Command Definition Contents

TABLES
CDU-1

Summary of CDU Operators

CDU-15

CDU—2

How the DEFINE SYNTAX Statement Modifies the Primary
DEFINE Statement

CDU-21

Preface

Intended Audience
This manual is intended for all system users who wish to define their own
DCL commands.

Structure of This Document
This document is composed of five major sections.
The Format Section is an overview of the Command Definition Utility and is
intended as a quick reference guide. The format summary contains the DCL
command that invokes the Command Definition Utility, listing all command
qualifiers and parameters. The usage summary describes how to invoke and
exit from the the Command Definition Utility, how to direct output, and any
restrictions you should be aware of. The statement and clause summary lists
all statements and clauses that can be used within the Command Definition
Utility.
The Description Section explains how to use the Command Definition Utility.
The Command Definition File Statements Section describes each statement
that can be used in a command definition file. Statements appear in
alphabetical order.
The Qualifier Section describes each DCL command qualifier. Qualifiers
appear in alphabetical order.
The Examples Section contains examples of common operations that you
perform with the Command Definition Utility.

Associated Documents
For related information about this utility, see the following documents:
•

VAX/VMS DCL Dictionary

•

Guide to Programming on VAX/VMS

Conventions Used in This Document
Convention

Meaning

[ret]

A symbol with a one- to three-character
abbreviation indicates that you press a key
on the terminal, for example, I RET | .

lCTRL/xl

The phrase CTRL/x indicates that you
must press the key labeled CTRL while
you simultaneously press another key, for
example, CTRL/C, CTRL/Y, CTRL/O.

vii

Preface

viii

Convention

Meaning

$ SHOW TIME
05-JUN-1985 11:55:22

Command examples show all output lines or
prompting characters that the system prints
or displays in black letters. All user-entered
commands are shown in red letters.

$ TYPE MYFILE.DAT

Vertical series of periods, or ellipsis, mean
either that not all the data that the system
would display in response to the particular
command is shown or that not all the data
a user would enter is shown.

file-spec,...

Horizontal ellipsis indicates that additional
parameters, values, or information can be
entered.

[logical-name]

Square brackets indicate that the enclosed
item is optional. (Square brackets are
not, however, optional in the syntax of a
directory name in a file specification or in
the syntax of a substring specification in an
assignment statement.)

quotation marks
apostrophes

The term quotation marks is used to refer
to double quotation marks ("). The term
apostrophe (7) is used to refer to a single
quotation mark.

New and Changed Features
Changes for the SET COMMAND Command
The following changes apply to the SET COMMAND command, which
invokes the Command Definition Utility.
•

A new qualifier, /REPLACE, has been added.

•

The /DELETE qualifier has been modified; /NODELETE is no longer
permitted.

Changes in Command Definition Files
The following changes affect how command definition files are written and
processed:
•

The VALUE(TYPE=type-name) clause has been added to allow the
definition of value types. Value types define the type of value that can be
used with parameters, qualifiers, or keywords. The Command Definition
Utility allows built-in and user-defined value types.

•

A new statement, DEFINE TYPE, can be used in conjunction with the
VALUE(TYPE=type-name) clause to define keywords that can be used as
values for parameters, qualifiers or other keywords.

•

A new clause, DISALLOW, disallows combinations of parameters,
qualifiers, or keywords in a command line. The DISALLOW clause
can be used in DEFINE SYNTAX and DEFINE VERB statements.

•

Forward references to DEFINE TYPE and DEFINE SYNTAX statements are
allowed. Therefore, a DEFINE statement can reference another DEFINE
statement that appears later in the command definition file.

•

Parameter definitions must be copied to syntax changes if the syntax
change defines additional parmeters.

•

A new statement, IDENT, can be used to provide identifying information
for object modules.

•

Image names specified with the IMAGE clause should be surrounded in
quotation marks.

•

Values in command definition file statements can be specified as symbols
or character strings. Character strings should be enclosed in quotation
marks, while symbols should not. For example, the ROUTINE clause
requires that the routine name be specified as a symbol. The descriptions
for each clause indicate how values should be specified.

Changes That are Incompatible With Version 3.0
The following technical changes are incompatible with the V3.0 version of the
Command Definition Utility.
•

The way parameters are defined in DEFINE SYNTAX statements has
changed. You must rewrite DEFINE SYNTAX statements if they contain
parameter definitions and if parameters are defined before the syntax
change (in the DEFINE statement that refers to the syntax change).
To correct the DEFINE SYNTAX statement, repeat the initial parameter
definitions and then define the new parameters.
ix

New and Changed Features

•

You should recompile object modules that were created with the Version
3.0 Command Definition Utility. Although the old object modules will
still work, DCL will perform certain conversions every time the modules
are used. Therefore, to improve performance, it is recommended that you
recompile object modules.
This version of the Command Definition Utility does not support
undocumented functions from Version 3.0.

Command Definition

Command Definition
The Command Definition Utility (CDU) creates, deletes, or changes
command definitions in a command table. As input, the CDU ac¬
cepts a command table and/or a file that contains command def¬
initions. The CDU processes this input to create a new command
table. The new table can be either executable code or an object
module.

FORMAT

SET COMMAND [file-spec[,...]]
Command Qualifiers

Defaults

/DELETE=(verb[,...])
/[NO]LISTING[=file-spec]
/OBJECT[=file-spec]
/[NO]OUTPUT[=file-spec]
/REPLACE
/TABLE[=file-spec]

None.
/NOLISTING
None.
/OUTPUT
See text.
/TABLE

Command Parameter

file-spec[,...]
Specifies the name of one or more command definition files. If you specify
two or more file specifications, separate them with commas. The default file
type is CLD.
Wildcard characters are allowed in the file specification.

usage summary

Invoking
Use the DCL command SET COMMAND to invoke the Command Definition
Utility. SET COMMAND has the following modes:
SET COMMAND/DELETE

Deletes command definitions from a command
table.

SET COMMAND/OBJECT

Creates an object module from a command
definition file.

SET COMMAND/REPLACE

Adds or replaces definitions in a command table
using definitions from a command definition file.

The /DELETE, /OBJECT, and /REPLACE qualifiers are mutually exclusive;
you can use only one SET COMMAND mode in a command string.

Exiting
When the CDU has finished processing the command definition file and/or
table, the DCL prompt reappears on your screen.

CDU—1

Command Definition

Directing Output
By default, SET COMMAND/DELETE and SET COMMAND/REPLACE
modify your process command table and return the modified table to your
process. You can modify a different input command table by using the
/TABLE command qualifier. You can write the command table to an output
file by using the /OUTPUT command qualifier.
SET COMMAND/OBJECT creates an object module with the same name as
the command definition file unless you specify an alternate file name.

Privileges/Restrictions
To modify the system command table in SYS$LIBRARY:DCLTABLES.EXE
you need SYSPRV privilege.

statements and
clauses

Statements
DEFINE SYNTAX syntax-name [verb-clause[,...]]
DEFINE TYPE type-name [type-clause[,...]]
DEFINE VERB verb-name [verb-clause[,...]]
IDENT ident-string
MODULE module-name
Verb Clauses for DEFINE SYNTAX
DISALLOW expression
IMAGE image-string
NODISALLOWS
NOPARAMETERS
NOQUALIFIERS
PARAMETER param-name [,param-clause[,...]]
QUALIFIER qual-name [,qual-clause[,...]]
ROUTINE routine-name
Verb Clauses for DEFINE VERB
DISALLOW expression
IMAGE image-string
NODISALLOWS
NOPARAMETERS
NOQUALIFIERS
PARAMETER param-name [,param-clause[,...]]
QUALIFIER qual-name [,qual-clause[,...]]
ROUTINE routine-name
SYNONYM synonym-name
Type Clause
KEYWORD keyword-name [,keyword-clause[,...]]
Parameter Clauses
DEFAULT
LABEL = label-name
PROMPT = prompt-string
VALUE [(param-value-clausef,...])]

CDU-2

Command Definition
Description

Qualifier Clauses
BATCH
DEFAULT
LABEL = label-name
NEGATABLE
NONNEGATABLE
PLACEMENT = placement-clause
SYNTAX = syntax-name
VALUE[(qual-value-clause[,...])]
Keyword Clauses
DEFAULT
LABEL = label-name
NEGATABLE
NONNEGATABLE
SYNTAX = syntax-name
VALUE[(key-value-clause[,...])]
Parameter Value Clauses
CONCATENATE
DEFAULT = default-string
LIST
NOCONCATENATE
REQUIRED
TYPE = type-name
Qualifier and Keyword Value Clauses
DEFAULT = default-string
LIST
REQUIRED
TYPE = type-name
Placement Clauses
GLOBAL
LOCAL
POSITIONAL

DESCRIPTION

The CDU allows you to use DCL command processing techniques to check
command syntax and execute commands. The following sections describe
•

How DCL processes commands

•

Ways to use the CDU

•

How to write command definitions

•

How to process command definitions

•

How to use command language routines in programs

CDU—3

Command Definition
Description

Command Processing
In order to write command definitions and modify command tables, you must
understand how the DCL command interpreter processes commands. To
process a command, DCL prompts for and accepts a command string. Then
DCL parses the command string using definitions in your process command
table. Your process command table contains a list of valid commands and
their attributes. DCL parses the command string from left to right.
To parse a command string, DCL calls the CLI$DCL__PARSE routine to
check each entity in the command string. If each entity is valid, DCL sets
up an internal representation of the command string. Then DCL uses the
CLI$DISPATCH routine to invoke the image or routine that executes the
command. If the command string is not valid, DCL issues an error message.
The image or routine that executes a command must call the CLI$PRESENT
and CLI$GET_VALUE routines to get information about the entities that were
present in the command string. The image or routine uses this information to
determine how to execute the command.

1.1

Parts of a Command String
A command string can contain the following entities:
Verb

Specifies the command to be executed.

Parameter

Specifies what the verb acts upon. The DCL command defini¬
tions describe the allowable parameter values for each command.
Some commands (SET and SHOW) accept keywords as param¬
eters. A keyword is a predefined string that can be used as a
value for a parameter, qualifier, or another keyword.

Qualifier

Describes or modifies the action taken by the verb. The DCL
command definitions indicate whether qualifiers can accept
values. Command definitions also describe the types of values
that can be specified. Examples of qualifier values include file
specifications, integer values, keywords, and character strings.

The following command string illustrates the components of a DCL command
line.
$ DIFFERENCES/MODE=ASCII MYFILE.DAT YOURFILE.DAT

DIFFERENCES is the verb and /MODE is a qualifier which has as its value
the keyword ASCII. MYFILE.DAT and YOURFILE.DAT are parameters that
must be specified as file specifications.
The following example shows a command that uses a keyword as a parameter
value:
$ SHOW DEFAULT

In this example, SHOW is the verb and DEFAULT is a keyword that is used
as a parameter.

CDU—4

Command Definition
Description

1.2

The System and Process Command Tables
The system command table is contained in the file
SYS$LIBRARY:DCLTABLES.EXE. By default, when you log in to VAX/VMS
this command table is copied to your process. DCL uses your process com¬
mand table to parse command strings.
Because you can change your process command table without affecting the
permanent table in SYS$LIBRARY, you do not need any special privileges to
modify your process command table. However, to modify the DCL command
table in SYS$LIBRARY:DCLTABLES.EXE, you need SYSPRV privilege.
The system command table is created from source files called command
definition files. A command definition file contains statements that name and
describe verbs. DIGITAL maintains the command definition files for DCL;
they are not shipped with your system.

Using the CDU
To use the CDU:
•

Determine what table you want to create or modify. In general, you will
modify your process command table or the DCL table in SYS$LIBRARY,
or you will create an object module for a new table.

•

Choose a name and syntax for the command(s) you are defining. Use a
text editor to create a command definition file that defines the command(s).

•

Use the DCL command SET COMMAND to add your command definition
file to the appropriate command table. You can modify your process
command table, or a specified command table file. You can also create an
object module from your command definition file.

•

Write the code for the image or routine that is invoked by the command
you are adding to the command table. Use the appropriate command
language routines in this code.

Note that the foreign command facility is an alternate way to define com¬
mand verbs. The foreign command allows you to pass information about a
command string to an image. However, if you use the foreign command fa¬
cility, your program must parse the command string; DCL does not parse the
command string for you. See the VAX/VMS DCL Dictionary for information
on how to define a foreign command.

Choosing a Table
The type of table you are modifying or creating affects the way that you
write a command definition, process this definition, and write the code that
executes your command.
The most common tables that you modify or create include:
•

Your process command table

•

The DCL table in SYS$LIBRARY

•

New tables that allow user-written programs to process commands

CDU—5

Command Definition
Description

3.1 Modifying Your Process Command Table
To add a command to your process command table, define the new command
in a command definition file. In the command definition, specify the name of
an image for the command to invoke. Then use the SET COMMAND com¬
mand to add the new command to your process command table and to copy
the new table back to your process. For example, the following command
adds a command in NEWCOMMAND.CLD to your process command table:
$ SET COMMAND NEWCOMMAND

Now you can enter the new command after the DCL prompt, and DCL will
parse the command and invoke the appropriate image. Note that when you
write the code to execute the new command, you must use the command lan¬
guage routines CLI$PRESENT and CLI$GET—VALUE to obtain information
about the command string.
To make the command in NEWCOMMAND.CLD available to you each time
you log in, include the SET COMMAND command in your LOGIN.COM file.
The first example in the Examples Section shows how to add a new command
to your process command table. This example also shows how to write a
program that is invoked by the new command.

3.2 Adding a Command to the DCL Command Table
To add a command to the DCL command table in SYS$LIBRARY, define the
command in a command definition file. In this definition, specify the name
of an image for the command to invoke. Then use the SET COMMAND
command to add the new definition to the DCL command table and copy
the new table back to SYS$LIBRARY. (You must have SYSPRV to change the
DCL command table.) For example:
$ SET COMMAND/TABLE=SYS$LIBRARY:DCLTABLES $_ /OUTPUT=SYS$LIBRARY:DCLTABLES NEWCOMMAND

Now any user who logs in will have this modified DCL table copied to his
/her process and will therefore be able to enter the new command after the
DCL prompt.

3.3 Creating an Object Module
To create an object module for a new command table, define the commands
in a command definition file. For each command, specify the name of
a routine in a program that executes the command. Then use the SET
COMMAND command to create an object module from this command
definition file. For example:
$ SET COMMAND/OBJECT NEWCOMMAND

Now link this object module with the program that uses the table. Note that
when you link a command table with a user-written program, the program
must perform the functions of a command interpreter. That is, the program
must obtain command strings and call the parsing routine CLI$DCL_PARSE
to verify and create an internal representation of the command string. The
program must also call CLI$DISPATCH to invoke the appropriate routine.
Each command routine must use the DCL interface routines (CLI$PRESENT
and CLI$GET_VALUE) to get information about the command string that
invoked the routine.

CDU-6

Command Definition
Description

The second example in the Examples Section shows how to write and process
command definitions for an object module. This example also shows how to
write a program that parses commands and invokes routines.

Writing a CFILE
A command definition file contains information that defines a command, its
parameters, qualifiers, and keywords. In addition, the command definition
file provides information about the image or routine that is invoked after the
command string is successfully parsed.
Use a text editor to create a command definition file that contains the state¬
ments you need to describe your new command(s); you can use clauses to
specify additional information for statements. The default file type for a
command definition file is CLD.
Use the following conventions in command definition files:
•

The exclamation point delimits comments in a command definition file; an
exclamation point causes all following characters on a line to be treated as
comments.

•

Any statement and its clauses can be broken into multiple lines; no
continuation character is necessary. (However, you cannot split names
across two lines.) If you place a statement on one line, you can separate
clauses in the statement with either commas or spaces.

•

You cannot abbreviate statement or clause names in the command defini¬
tion language; all names (for example, DEFINE SYNTAX, PARAMETER)
must be spelled out completely.

Most statements and clauses accept user-supplied information such as verb
names, qualifier names, image names, and so on. You can specify this
information as a symbol or as a string. If the statement requires that a term
be specified as a string, enclose the term in quotation marks. A string can
contain any alphanumeric or special characters. To include quotation marks
within a string, use double quotation marks ("").
Note: To maintain compatibility with earlier releases, the CDU accepts char¬
acter strings that are not enclosed in quotation marks. However, it is
recommended that you surround character strings in quotation marks. If
you do not enclose a string in quotation marks, alphabetic characters are
converted to uppercase.
If a statement requires that a term be specified as a symbol, do not enclose
the term in quotation marks. A symbol name can contain between 1 and 31
characters, must start with a letter or a dollar sign, and can contain letters,
numbers, dollar signs, and underscore characters.
The Command Definition Utility Language includes the following statements:
•

DEFINE SYNTAX syntax-name [verb-clause[,...]]

•

DEFINE TYPE type-name [type-clause[,...]]

•

DEFINE VERB verb-name [verb-clause[,...]]

CDU—7

Command Definition
Description

•

IDENT

•

MODULE module-name

The following sections provide a general overview of each CDU statement;
complete information is given in the Command Definition File Statements
Section that follows this description.

4.1

Defining Command Verbs
The DEFINE VERB statement defines a new command verb and specifies
different characteristics for this verb. You can define any number of verbs in
a single command definition file.
The format for the DEFINE VERB statement is
DEFINE VERB verb-name [verb-clause[,...]]

The verb name is the name of the command. A verb clause specifies addi¬
tional information about the verb. Verb clauses can appear in any order in
the command definition file. Use of verb clauses is optional.
You can specify the following verb clauses:
DISALLOW

Restricts use of an entity or a combination of entities.

IMAGE

Specifies an image to be invoked by the verb.

NODISALLOWS

Indicates that no entities or combinations of entities are
disallowed.

NOPARAMETERS

Indicates that no parameters are allowed.

NOQUALIFIERS

Indicates that no qualifiers are allowed.

PARAMETER

Defines a parameter that can be specified.

QUALIFIER

Defines a qualifier that can be specified.

ROUTINE

Specifies a routine to be invoked by the verb.

SYNONYM

Specifies a verb synonym.

The following example illustrates a DEFINE VERB statement:

DEFINE VERB SEARCH
IMAGE "SEARCH"
©
PARAMETER PI, LABEL=SOURCE, PROMPT="File", VALUE(REQUIRED)

© The DEFINE VERB statement names the verb "search."
© The IMAGE verb clause identifies the image to be invoked at run time.
© The PARAMETER verb clause defines the first parameter to appear after
the verb on the command line. LABEL, PROMPT, and VALUE are
parameter clauses that further define the parameter. LABEL defines a
name that the image uses to refer to the parameter. PROMPT indicates
the prompt string to be issued if you do not specify the parameter in the
command string. VALUE uses the REQUIRED clause to indicate that the
parameter must be present in the command string.
For complete information on the DEFINE VERB statement and its verb
clauses, see the Command Definition File Statements Section.

CDU—8

Command Definition
Description

4.2

Defining Syntax Changes With the DEFINE SYNTAX Statement
The DEFINE SYNTAX statement defines a syntax change that replaces a
command's syntax (as defined in a DEFINE VERB, DEFINE TYPE, or in
another DEFINE SYNTAX statement). A syntax change allows a verb to use
a different syntax depending on the parameters, qualifiers, and keywords that
are present in the command string.
To indicate a syntax change, the DEFINE VERB statement that defines an
entity (the primary DEFINE statement) must include a SYNTAX=syntax-name
clause to point to the alternate syntax. The alternate syntax is the secondary
DEFINE statement.
For example, you can write a command definition that uses a different syntax
if a certain qualifier is present. When you specify this qualifier, the syntax
defined in the secondary DEFINE statement applies to the command string.
The format for the DEFINE SYNTAX statement is
DEFINE SYNTAX syntax-name [verb-clause,[,...]]

The syntax name is the name of the alternate syntax definition. The verb
clause specifies additional information about the syntax. You can use the
same verb clauses in a DEFINE SYNTAX statement as are allowed in a
DEFINE VERB statement, with one exception. You cannot use the SYN¬
ONYM verb clause with DEFINE SYNTAX.
The following example shows how a syntax change is used to specify an
alternate command syntax when the /LINE qualifier is specified.
DEFINE VERB ERASE
IMAGE "DISKI:[MYDIR]ERASE"
QUALIFIER SCREEN
QUALIFIER LINE, SYNTAX=LINE

DEFINE SYNTAX LINE
©
IMAGE "DISKI:[MYDIR]LINE"
QUALIFIER NUMBER, VALUE(REQUIRED)

© The DEFINE VERB defines the verb, ERASE. This verb accepts two quali¬
fiers, /SCREEN and /LINE. The qualifier /LINE uses an alternate syntax,
specified with the SYNTAX=LINE clause. If you issue the command
ERASE/LINE, the definitions in the DEFINE SYNTAX LINE statement
override the definitions in the DEFINE VERB ERASE statement. However
if you issue the command ERASE/SCREEN, or if you do not specify any
qualifiers, the definitions in the DEFINE VERB ERASE statement apply.
© The DEFINE SYNTAX statement defines an alternate syntax called LINE.
If you issue the command ERASE with the /LINE qualifier, the image
DISK 1:[MYDIRJLINE.EXE is invoked. The new syntax allows the qualifier
/NUMBER, which requires a value.
For complete information on the DEFINE SYNTAX statement and its verb
clauses, see the Command Definition File Statements Section.

CDU-9

Command Definition
Description

4.3

Defining Values for Parameters, Qualifiers, and Keywords
To indicate that a parameter, qualifier, or keyword requires a value, use the
VALUE clause. When you use the VALUE clause, you can further define the
value type with the TYPE clause.
With the TYPE clause, you can specify that a value must be a built-in type
(for example, the value must be a file specification) or you can specify that a
value must be a user-defined keyword. Section 4.3.1 lists the built-in value
types; Section 4.3.2 describes how to specify a user-defined keyword.
When you use the VALUE clause and do not define a value type, DCL
processes the value in the following way. If the value is not enclosed in
quotation marks, then DCL converts letters to uppercase and compresses mul¬
tiple spaces and tabs to a single space. If the value is enclosed in quotation
marks, then DCL removes the quotation marks, preserves the case of letters,
and does not compress tabs and spaces. To include quotation marks within
a quoted string, use double quotation marks ("") in the place you want the
quotation marks to appear.

4.3.1

Built-In Types
The Command Definition Language provides the following built-in types:
$ACL

The value must be an access control list.

SDATETIME

The value must be an absolute or a combination time.
DCL converts truncated time values, combination
time values, and keywords for time values (such
as TODAY) to absolute time format. If the value is
missing any date fields, DCL fills in the current date.
If the value is missing any time fields, DCL fills these
fields with zeros.

SDELTATIME

The value must be a delta time. If the value is missing
any time fields, DCL fills these fields with zeros.

$FILE

The entity value must be a valid file specification.

$NUMBER

The entity value must be an integer. The command
string can contain decimal, octal, or hexadecimal
numbers. However, DCL converts all numbers to
decimal.

$QUOTED_STRING

DCL uses the default method of processing the entity,
with one exception. DCL does not remove quotation
marks when processing the string.

$REST_OF_LINE

Everything until the end of the the line is equated to
the entity value.

The following example shows a parameter that must be specified as a file
specification:
DEFINE VERB PLAY
IMAGE "DISKI:[MYDIR]PLAY"
PARAMETER PI, VALUE(TYPE=$FILE)

CDU-10

Command Definition
Description

4.3.2

User-Defined Keywords
The DEFINE TYPE statement defines keywords that can be used as values for
parameters, qualifiers, or other keywords. The keywords listed in a DEFINE
TYPE statement are the only values that can be used with the corresponding
parameter, qualifier, or keyword.
To indicate that a parameter, qualifier, or keyword requires a keyword,
use the VALUE(TYPE=type-name) clause when the entity is defined. The
type name refers to the DEFINE TYPE statement that defines the allowable
keywords. When you use VALUE(TYPE=type-name), this starts a keyword
path.
The format for the DEFINE TYPE statement is
DEFINE TYPE type-name

[type-clause[,...]]

The type name is the name of the keyword list. The type clause specifies
allowable keywords and provides information about each keyword.
You can use the following type clause:
KEYWORD

Defines a keyword that can be used with the parameter, qualifier, or
keyword that references the keyword list.

This example illustrates a DEFINE TYPE statement:

DEFINE VERB SKIM
IMAGE "USER:[TOOLS]SKIM"
QUALIFIER SPEED, VALUE(TYPE=SPEED_KEYWORDS)

DEFINE TYPE SPEED_KEYWORDS
©
KEYWORD FAST, DEFAULT
KEYWORD SLOW

O The DEFINE VERB statement defines a verb, SKIM, which accepts the
qualifier SPEED. The verb SKIM invokes the image [TOOLSJSKIM.EXE
and accepts the qualifier /SPEED.
© The VALUE clause indicates that the qualifer /SPEED accepts a list of
keywords. These keywords are defined in the DEFINE TYPE SPEED—
KEYWORDS statement.
© The DEFINE TYPE statement lists the keywords that can be specified
with the qualifier /SPEED; you can specify SKIM/SPEED=FAST or SKIM
/SPEED=SLOW. If you specify the qualifier /SPEED without a value, the
default is FAST.
For complete information on the DEFINE TYPE statement and the KEYWORD
type clause, see the Command Definition File Statements Section.

4.4

Disallowing Combinations of Entities in Command Definitions
When you use DEFINE statements, you can indicate that an entity (a param¬
eter, qualifier, or keyword) or a combination of entities is invalid in certain
cases. To prohibit use of an entity or a combination of entities, use the
DISALLOW verb clause.
The DISALLOW verb clause has the following format:
DISALLOW expression

CDU-11

Command Definition
Description

The expression specifies an entity in a command string, or a group of entities
connected by operators. When a command string is parsed, each entity in
the expression is tested to determine if the entity is present (true) or absent
(false). If an entity is present by default, but is not explicitly present in the
command string, the entity is evaluated as absent (false).
After each entity is evaluated, the operations indicated by the operators are
performed. If the result is true, the command string is disallowed. If the
result is false, the command string is valid.
For example, a command definition may contain a DEFINE VERB statement
that defines the verb SPORTS with three qualifiers: /TENNIS, /BOWLING,
and /BASEBALL. However, you may want to make the qualifiers mutually
exclusive. The following example shows how to use the DISALLOW verb
clause to put this restriction into the command definition file:
DEFINE VERB SPORTS
IMAGE "DISK3:[WILSON]SPORTS"
QUALIFIER TENNIS
QUALIFIER BOWLING
QUALIFIER BASEBALL
DISALLOW ANY2(TENNIS. BOWLING. BASEBALL)

The DISALLOW verb clause indicates that a command string is invalid
if it contains more than one of the qualifiers /TENNIS, /BOWLING, or
/BASEBALL.
Note that when you specify any entity in a DISALLOW expression, the search
context is the entire command line. Therefore, local qualifiers are treated as
if they were global for the purposes of the DISALLOW processing. The
following example shows the global context of the search:
DEFINE VERB TEST
IMAGE
"DISK3: [WORK]TEST"
PARAMETER
PI
PARAMETER
P2
QUALIFIER
QUAL1
QUALIFIER
QUAL2.P0SITI0N=L0CAL
QUALIFIER
QUAL3.P0SITI0N=L0CAL
DISALLOW
PI AND QUAL1
DISALLOW
QUAL2 AND QUAL3

Thus, the following two command lines would be disallowed:
TEST PI P2/QUAL1
TEST P1/QUAL2 P2/QUAL3

The global search context applied to local qualifiers is used only with
DISALLOW processing, not with normal command parsing.

4.4.1

Specifying Entities in an Expression
When you specify entities in an expression, you need to uniquely identify
the entities that are disallowed. You can specify an entity using one of the
following:

CDU—12

•

A parameter, qualifier, or keyword name or label

•

A keyword path

•

A definition path

Command Definition
Description

Names and Labels
You can refer to a parameter or qualifier using its name or label if the entity
is defined in the current definition. To refer to a keyword, you can use its
name or label if the keyword is in a keyword path that starts from the current
definition, and the keyword name or label is unique. (See the next section for
more information on keyword paths.)
If the LABEL=label-name keyword is used to assign a label to an entity, you
must use the label to refer to the entity. Otherwise use the entity name.
The following example disallows combinations of entities:
DEFINE VERB COLOR
IMAGE "WORK:[JUDY]COLOR"
QUALIFIER RED
QUALIFIER BLUE
QUALIFIER GREEN. VALUE(TYPE=GREEN_AMOUNT)
DISALLOW RED AND ALL
DISALLOW BLUE AND ALL
DEFINE TYPE GREEN_AMOUNT
KEYWORD ALL
KEYWORD HALF

In this example, you can use the parameter and qualifier names RED and
BLUE in the DISALLOW verb clause because both names are used in the
current definition. You can use the keyword name ALL because it is in a
keyword path which starts within the current definition (the TYPE=GREEN_
AMOUNT qualifier clause starts the path) and the keyword name is unique.
The DISALLOW clauses indicate that the following command strings are not
valid:
$ COLOR/RED/GREEN=ALL
$ COLOR/BLUE/GREEN=ALL

To refer to a parameter or qualifier in another definition, or to refer to a
keyword whose path begins in another DEFINE statement, you must use a
definition path.

Keyword Paths
A keyword path provides a way to uniquely identify a keyword. You can
refer to a keyword using a keyword path if the keyword is in a path that
starts from the current definition, and the keyword name or label is not
unique. You can also use a keyword path if the same keyword can be used
with more than one parameter or qualifier.
A keyword path contains a list of entity names or labels that are separated by
periods. The first name in a keyword path is the name (or label) of the first
entity in the path that references the keyword's type definition. A keyword
path can contain up to eight names (the first parameter or qualifier definition,
plus seven DEFINE TYPE keyword definitions).
If a keyword is assigned a label name, you must use the label name in the
keyword path. Otherwise, use the keyword name. You can omit names from
the beginning of a keyword path that are not needed to resolve a keyword
reference. However, you must include enough names to uniquely reference
the keyword.
The following command string illustrates a situation where keyword paths are
needed to uniquely identify keywords. In this command string, you can use
the same keywords with more than one qualifier. (In the command definition
file, two qualifiers refer to the same DEFINE TYPE statement.)

CDU—13

Command Definition
Description

$ NEWC0MMAND/QUAL1=(START=5.END=10)/QUAL2=(START=2,END=5)

The keyword path QUAL1.START identifies the keyword START when it is
used with QUAL1; the keyword path QUAL2.START identifies the keyword
START when it is used with QUAL2. The name START is an ambiguous
reference if used alone.
To disallow use of the keyword QUAL1.START when a third qualifier
(QUAL3) is present, use the following line in the command definition file:
DISALLOW QUAL1.START AND QUAL3

Although you cannot use QUAL1.START when QUAL3 is present, you can
still use QUAL2.START with QUAL3.
The following example contains a keyword (ALL) that appears in two DEFINE
TYPE statements:
DEFINE VERB COLOR
IMAGE "WORK:[JUDY]COLOR"
QUALIFIER RED. VALUE(TYPE=RED_AMOUNT)
QUALIFIER GREEN. VALUE(TYPE=GREEN.AMOUNT)
DISALLOW RED AND GREEN.ALL
DISALLOW GREEN AND RED.ALL
DEFINE TYPE RED.AMOUNT
KEYWORD ALL
KEYWORD MIXED
DEFINE TYPE GREEN.AMOUNT
KEYWORD ALL
KEYWORD HALF

In this example, you must use the keyword path RED.ALL to refer to the ALL
keyword when it is used in the type definition RED__AMOUNT; you must
use the keyword path GREEN.ALL to refer to the ALL keyword when it is
used in the type definition GREEN-AMOUNT.

Definition Paths
A definition path is used to refer to an entity that is defined in another
DEFINE statement. Use a definition path in a syntax definition when param¬
eters or qualifiers are inherited from a primary definition, but new disallow
clauses are provided.
A definition path has the format
<definition-name>entity-8pec

The definition name is the name of the DEFINE statement where the entity is
defined or the keyword path begins. The entity spec can be an entity name, a
label, or a keyword path. The angle brackets are required syntax.
For example:
DISALLOW <SKIP>FIRST

This clause disallows a command string if the entity FIRST (which is defined
in a DEFINE statement named SKIP) is present.
The next example uses a keyword path and a definition path:
DISALLOW <FILE>BILLS.ELECT AND GAS

This clause disallows a command string if the entity described by the keyword
path BILLS.ELECT (which starts in a DEFINE statement named FILE) is
present.

CDU-14

Command Definition
Description

The CDU does not check a definition path to determine that the path refers to
an entity that is valid in a given context. If you use a definition path to spec¬
ify an entity that is not valid in a particular context, results are unpredictable.
The following example shows a definition path that is not valid in the syntax
definition where it is used.
DEFINE VERB FILE
QUALIFIER BILLS. SYNTAX=BILL_TYPES
QUALIFIER RECEIPTS
DEFINE VERB READ
QUALIFIER NOTES
DEFINE SYNTAX BILL.TYPES
DISALLOW <READ>NOTES

Although the DISALLOW clause correctly identifies an entity in the command
definition file, this entity is not valid in the DEFINE SYNTAX statement.
The clause DISALLOW <FILE> RECEIPTS would have been valid in the
DEFINE SYNTAX statement, however. The DEFINE SYNTAX statement
inherits the qualifier RECEIPTS from the primary DEFINE statement (FILE)
because no qualifiers are specified. Therefore, the qualifier RECEIPTS can
be disallowed. See the description of the DEFINE SYNTAX statement in
the Command Definition File Statements Section for more information on
how entities are inherited by DEFINE SYNTAX statements.
4.4.2

Operators
If an expression contains operators, the operators are evaluated after the
entities are evaluated as present (true) or absent (false). If the result of
the expression is true, then the syntax is disallowed. If the result of the
expression is false, then the syntax is valid.
Table CDU-1 shows the operators you can use in expressions and the order
in which these operators are evaluated. (Operators with a precedence of 1 are
performed first.) Operations of the same precedence are performed from left
to right, in the order they appear in the expression.
Table CDU-1

Summary of CDU Operators

Operator

Precedence

Meaning

ANY2(entity[,...])

Result is true if any two or more of the
entities listed are present.

NEG entity

Result is true if the negated form of the
entity is present.

NOT entity

Result is true if the entity is not present
or if an entity is present by default.

exp AND exp

Result is true if both expressions are
true.

exp OR exp

Result is true if either expression is
true.

The following example shows how to use the AND operator:
DISALLOW TERMINAL AND PRINTER

This statement disallows the command string if both entities (TERMINAL and
PRINTER) are present.

CDU-15

Command Definition
Description

You can use parentheses to override the order in which operations are
evaluated; operations within parentheses are evaluated first. For example:
DISALLOW FAST AND

(SLOW OR STILL)

The parentheses force the OR operator to be evaluated before the AND
operator. Therefore, if the result of SLOW OR STILL is true, and if FAST is
present in the command string, then the string is disallowed.

4.5

Providing Identifying Information for Object Modules
Use the MODULE and IDENT statements to provide identifying information
if your command definition file will be used to create an object module.
(You can create an object module from a command definition file with
the command SET COMMAND/OBJECT. The object module contains a
command table which you can link with a user-written program.)
The MODULE statement assigns a symbolic name to the object module
containing the command table. The format for the MODULE statement is
MODULE module-name

The module name is the symbolic name for the object module.
The IDENT statement provides additional information to identify the module.
The format for the IDENT statement is
IDENT ident-string

The following command definition file shows how to use the MODULE and
IDENT statements:
MODULE TABLE

IDENT "Updated 4/15/84"
DEFINE VERB SAVE

ROUTINE SAVE.ROUT
DEFINE VERB GET

ROUTINE GET.ROUT

© The MODULE statement assigns the name TABLE to the table that
is created when an object module is created with the command SET
COMMAND/OBJECT.
© The IDENT statement provides additional identifying information. In
this example, it shows the date when the command definition file was
updated.
© The DEFINE VERB statements define verbs that can be used by the userwritten program that will be linked with the object module containing
the command table. Each verb invokes a routine within the user-written
program.

CDU-16

Command Definition
Description

Processing the Command Definition File
A command definition file must be translated into an executable command
table before the commands in the table can be parsed and executed. To
perform this translation, use the DCL command SET COMMAND to invoke
the Command Definition Utility.
The command SET COMMAND has the following modes:

SET COMMAND/DELETE

Deletes command definitions from a command
table

SET COMMAND/OBJECT

Creates an object file from a command definition
file

SET COMMAND/REPLACE

Adds or replaces definitions in a command table
using definitions from a command definition file

The /DELETE, /OBJECT, and /REPLACE qualifiers are mutually exclusive;
thus you can use only one SET COMMAND mode on a command line. In
addition to the qualifiers which specify modes, SET COMMAND provides the
following qualifiers:

/[NOjLISTING

Controls whether an output listing is created

/[NOjOUTPUT

Controls where the modified command table should be
written

/TABLE

Specifies the command table that is to be modified

See the Qualifiers Section for complete information on using the SET
COMMAND qualifiers.

5.1

Adding Command Definitions to a Command Table
Use the /REPLACE qualifier to add or replace verbs in the command table
you are modifying. By default, SET COMMAND uses /REPLACE mode to
add commands to your process command table and returns the modified
command table to your process.
The following example shows how to add the new command SKIP to your
process command table:
$ SET COMMAND SKIP

In this example, SET COMMAND adds the definitions from the command
definition file SKIP.CLD to your process command table. The modified table
replaces your original process command table. The /REPLACE qualifier is
present by default, so you do not need to explicitly specify it in the command
string.
To modify a table other than your process table, use the /TABLE qualifier to
specify an input table; if you want to write the modified table to a file (instead
of to your process), use the /OUTPUT qualifier.

CDU-17

Command Definition
Description

5.2 Deleting Command Definitions
Use the /DELETE qualifier to delete a command name from a command
table. By default, commands are deleted from your process command table.
The following example shows how to delete the command SKIP from your
process command table:
$ SET COMMAND/DELETE=SKIP

5.3 Creating an Object Module
Use the /OBJECT qualifier to create an object module from a command
definition file. The following example shows how to create an object module:
$ SET COMMAND/OBJECT NEWCOMS

Entering SET COMMAND with the /OBJECT qualifier creates an object
module containing a command table with the verb definitions in
NEWCOMS.CLD. You can link this module with a program that parses
commands using the linked command table module.

5.4 Creating a New Command Table
You cannot use the /OBJECT qualifier to create an object module from a
command definition file that contains the IMAGE clause. However, you can
create an empty command table to which verbs that invoke images can be
added.
To create an empty command table, create a command definition file that
uses the MODULE statement to define a module name and optionally uses
the IDENT statement. For example, the command definition file TESTTABLE.CLD contains:
MODULE TEST.TABLE
IDENT "New command table"

Create an object module from TEST-TABLE.CLD, and link it to create a
shareable image:
$ SET COMMAND/OBJECT TEST.TABLE.CLD
$ LINK/SHARE TEST.TABLE

Next, create a command definition file that defines verbs that invoke images.
For example, the command definition file VERBS.CLD contains:
DEFINE VERB PASS
IMAGE "DISK4:[ROSEN]PASS"
DEFINE VERB THROW
IMAGE "DISK4:[ROSEN]THROW"

Then add the new commands in VERBS.CLD to the empty command table
in TEST_TABLE.EXE and write the modified table back to the file TEST—
TABLE.EXE. (The resulting file will have a version number of one greater
than the version number of the input table.) For example:
$ SET COMMAND/TABLE=TEST_TABLE.EXE/OUTPUT=TEST_TABLE.EXE VERBS

CDU-18

Command Definition
Description

The /TABLE and /OUTPUT qualifiers specify the input and output table files,
Be sure to use the /OUTPUT qualifier to specify the output file. Otherwise,
the modified command table will be written to your process and will replace
your process command table.

Using Command Language Routines
A user-written program invoked by a command that you have added to your
process (or system) command table will need information about the command
string that invoked it. Call DCL's command language interface routines from
your program to retrieve this information.
There are two command language interface routines:
CLI$PRESENT

Determines if an entity is present in the command string.

CLI$GET_VALUE

Gets the value of the next entity in the command string.

If a program is using its own command table (that is, the command table has
been linked with the program) the program can call DCL's command parsing
routines to parse the command string and invoke the appropriate routine to
execute the command. The routine then calls CLI$PRESENT and CLI$GET_
VALUE to obtain information about the command string.
There are two command parsing routines:
CLISDCI_PARSE

Parses a command string.

CLISDISPATCH

Invokes the routine which corresponds to the verb most
recently parsed.

The Examples Section shows two programs that call these routines. For com¬
plete information on the command language routines and their arguments,
see the VAX/VMS Utility Routines Reference Manual.

CDU-19

Command Definition
Command Definition File Statements

This section provides complete information on the statements that can be
COMMAND
used in a command definition file. The statements are
DEFINITION
DEFINE SYNTAX
FILE
DEFINE TYPE
STATEMENTS
DEFINE VERB
IDENT
MODULE

CDU-20

Command Definition
DEFINE SYNTAX

DEFINE SYNTAX
Defines a syntax change that replaces a command's syntax (as de¬
fined in a DEFINE VERB, DEFINE TYPE, or another DEFINE SYNTAX
statement). A syntax change allows a verb to use a different syn¬
tax depending on the parameters, qualifiers, and keywords that are
present in the command string.
The DEFINE statement that refers to a changed syntax is called a
primary define statement. The DEFINE SYNTAX statement that
defines the new syntax is called a secondary DEFINE statement.
When a command string is parsed, its components are scanned
from left to right. The line is parsed according to the current defini¬
tion until an entity occurs that specifies a syntax change. Then, the
following entities are parsed using the new definition. DCL does not
rescan the entities that appeared before the entity that specified the
syntax change.
Table CDU-2 explains how the DEFINE SYNTAX statement mod¬
ifies the current command definition if an entity specifies a syntax
change. The command definition that exists after the last entitity
in the command string has been parsed is saved by DCL. DCL uses
the disallows in this definition to determine if any entities are not
allowed. Then, DCL invokes the image or routine specified by the
saved definition and uses this definition to process CLI$PRESENT
and CLI$GET_VALUE calls.
Table CDU-2

How the DEFINE SYNTAX Statement Modifies
the Primary DEFINE Statement

DEFINE SYNTAX Specifies

Result

An image

This image overrides the image in the
primary DEFINE statement. DCL invokes
the new image after it parses the command
string.

A routine

This routine overrides the routine in the
primary DEFINE statement. DCL invokes the
new routine when CLISDISPATCH is called.

One or more disallows

These disallows are used during command
parsing; disallows in the primary DEFINE
statement are ignored. This applies to all
entities in the command that have not been
invalidated by the new syntax definition.

No disallows

Disallows from the primary DEFINE state¬
ment are used during command parsing.

The NODISALLOWS clause

No disallows are permitted, regardless of
definitions in the primary DEFINE statement.

CDU-21

Command Definition
DEFINE SYNTAX

Table CDU-2 (Cont.)

How the DEFINE SYNTAX Statement
Modifies the Primary DEFINE Statement

DEFINE SYNTAX Specifies

Result

One or more parameters

Parameters that were already parsed are
not reparsed according to the new defini¬
tions. However, parameters to the right
of the entity that specified the new syn¬
tax will be parsed according to the new
definitions. DCL uses the new parameter
definitions when processing CLI$PRESENT
and CLI$GET_VALUE calls.
Note that in the DEFINE SYNTAX state¬
ment, PI still refers to the first parameter
in the command string. Therefore, if you
want to define parameters in addition to
parameters defined in the primary DEFINE
statement, you must use the PARAMETER
clause to redefine the original parameters
in the secondary DEFINE statement. Define
these parameters exactly as they appeared
in the primary DEFINE statement. Then,
define the new parameters.

No parameters

Parameter definitions from the primary
DEFINE statement are used when DCL
parses the remainder of the command
string. DCL also uses these parameter
definitions when processing CLI$PRESENT
and CLI$GET_VALUE calls.

The NOPARAMETERS clause

Parameters that were already parsed are not
reparsed according to the new definitions.
However, no parameters are allowed when
DCL parses entities to the right of the
entity that specifies the new syntax. DCL
uses the NOPARAMETERS definition when
processing CLI$PRESENT and CLI$GET_
VALUE calls.

One or more qualifiers

Qualifiers that were already parsed are
ignored. If the entity that specifies the
syntax change is a qualifier, this qualifier is
also ignored. Qualifiers that appear in the
command line after the entity that specifies
the new syntax will be parsed according
to the new definitions. DCL uses the
new qualifier definitions when processing
CLI$PRESENT and CLI$GET_VALUE calls.
When DCL parses a command line that
contains qualifiers that are ignored (due to
a syntax change), DCL issues a warning
message.

CDU-22

Command Definition
DEFINE SYNTAX

Table CDU-2 (Cont.)

FORMAT

How the DEFINE SYNTAX Statement
Modifies the Primary DEFINE Statement

DEFINE SYNTAX Specifies

Result

No qualifiers

Qualifier definitions from the primary DEFINE
statement are used when DCL parses the
remainder of the command string. DCL
also uses these qualifier definitions when
processing CLI$PRESENT and CLI$GET_
VALUE calls.

The NOQUALIFIERS clause

Qualifiers that were already parsed are
ignored. No qualifiers are allowed when
DCL parses entities to the right of the entity
that specifies the new syntax. DCL uses the
NOQUALIFIERS definition when processing
CLISPRESENT and CLI$GET_VALUE calls.

DEFINE SYNTAX syntax-name[verb-clause[,...]]
syntax-name
The name of the syntax change. The name is required and must immediately
follow the DEFINE SYNTAX statement.

verb-clause[,...]
Specify optional verb clauses that define attributes of the command string.
DEFINE SYNTAX accepts the following verb clauses:
•

DISALLOW, NODISALLOWS

•

IMAGE

•

PARAMETER, NOPARAMETERS

•

QUALIFIER, NOQUALIFIERS

•

ROUTINE

These clauses are described below.

DISALLOW expression
NODISALLOWS
Disallows a command string if the result of the expression is true. The
NODISALLOWS clause indicates that no entities or combinations of entities
are disallowed.
The expression specifies an entity or a combination of entities connected by
operators. Each entity in the expression is tested to see if it is present (true)
or absent (false) in a command string. If an entity is present by default but is
not explicitly provided in the command string, the entity is false.
After each entity is evaluated, the operations indicated by the operators are
performed. If the result is true, the command string is disallowed. If the
result is false, the command string is valid.

CDU-23

Command Definition
DEFINE SYNTAX

You can specify entities in an expression using an entity name or label, a
keyword path, or a definition path. See Section 4.4.1 for more information
on these entities. You can specify the operators AND, ANY2, NEG, NOT,
OR, or ANY2. See Section 4.4.2 for more information on these operators.

IMAGE image-string
Names an image to be invoked for the syntax change. The image-string is
the file specification of the image that DCL invokes when you issue the com¬
mand. If you do not provide a complete file specification, the command lan¬
guage interpreter supplies a default directory specification of SYS$SYSTEM:
and a default file type of EXE. Specify the image string as a character string
that does not exceed 63 characters.
If you do not specify an IMAGE verb clause (and you use SET COMMAND
/REPLACE to process the command definition), the CDU uses the image
name from the DEFINE statement that references the syntax change. If this
DEFINE statement does not contain an image name, the CDU checks to
see if the DEFINE statement is pointed to by another DEFINE statement. It
keeps searching until it finds the name of an image to invoke. If no image
is specified, then DCL searches, at run time, for an image whose file name
is the same as the verb name and whose device name and file type are
SYS$SYSTEM: and EXE, respectively.

PARAMETER param-name [,param-clause[,...]]
NOPARAMETERS
Specifies whether parameters can be included in the command string. You
can use the PARAMETER clause up to eight times in a DEFINE SYNTAX
statement. The NOPARAMETERS clause indicates that no parameters are
allowed.
The param-name is the position of the parameter in the command line. The
name must be in the form Pn, where n is the position of the parameter. The
parameter names must be numbered consecutively from PI to P8. The name
must immediately follow the PARAMETER clause.
The param-clauses specify additional chacteristics for the parameter. You can
use the following parameter clauses:
•

DEFAULT

•

LABEL=label-name

•

PROMPT=prompt-string

•

VALUE[(param-value-clause[,...])]

CDU-24

Command Definition
DEFINE SYNTAX

PROMPT=prompt-string supplies a prompt string for a parameter that is not
entered in the command string. If you do not specify a prompt string and
a required parameter is missing, DCL will use the parameter name as the
prompt string. Specify the prompt string as a character string that does not
exceed 31 characters.
If you define more than one parameter and the first parameter is required but
the other parameters are optional, then prompting is done in the following
way. If the user types the command without any parameters, DCL will
prompt for the first (required) parameter until the user types a value, or
aborts the command with a CTRL/Z.
After the user types a value for PI, DCL will prompt for subsequent parame¬
ters, even though these parameters are optional. After the prompt, if the user
types a CTRL/Z, the command is aborted. If the user presses the return key
without entering a value, the command is executed. If the user types a value,
then DCL prompts for the next optional parameter.
VALUE[(param-value-clause[,...])] specifies additional characteristics for
the parameter. When you specify parameter value clauses, enclose them in
parentheses and separate items with commas.
VALUE accepts the following parameter value clauses:
CONCATENATE

Indicates that a parameter can be concatenated
to another parameter with a plus sign.

DEFAULT=default-string

Specifies a default value to be used in the
absence of an explicit parameter value. The
DEFAULT clause and the REQUIRED clause are
mutually exclusive. Specify the default string
as a character string that does not exceed 95
characters.
Do not use this clause to specify a default
if the value is a keyword; specify keyword
defaults in the DEFINE TYPE statement and by
using the DEFAULT parameter clause.

LIST

Indicates that a list of parameters separated by
commas or plus signs can be specified.

NOCONCATENATE

Indicates that the parameter cannot be con¬
catenated to another parameter with a plus
sign.

REQUIRED

Indicates that the parameter is required. All
required parameters must precede optional
ones. If you use the REQUIRED clause, you
should also specify a prompt string.
The REQUIRED clause and the DEFAULT clause
are mutually exclusive.

TYPE=type-name

Gives either a built-in type or the name of
a DEFINE TYPE statement that defines a
list of keywords that can be specified for
the parameter. Specify the type name as a
symbol.
See Section 4.3.1 for more information on
built-in types.

CDU-25

Command Definition
DEFINE SYNTAX

QUALIFIER qual-name [,qual-clause[,...]]
NOQUALIFIERS
Specifies a qualifier that can be included in the command string. You can use
the QUALIFIER clause up to 255 times in a DEFINE SYNTAX statement. The
NOQUALIFIERS clause indicates that no qualifiers are allowed.
The qual-name is the name of the qualifier. Specify the qualifier name as a
symbol. The first four characters of the qualifier name must be unique.
The qual-clause specifies additional qualifier characteristics. You can use the
following qualifier clauses:
•

BATCH

•

DEFAULT

•

LABEL=label-name

•

NEGATABLE, NONNEGATABLE

•

PLACEMENT=placement-clause

•

S YNT AX=syn tax-name

•

VALUE[(qual-value-clause[,...])]

BATCH indicates that the qualifier is present by default if the command is
used in a batch job.
DEFAULT indicates that the qualifier is present by default in both batch and
interactive jobs.
LABEL=label-name defines a label for requesting information about the
qualifier at run time. Specify the label name as a symbol. If you do not
specify a label name, the qualifier name is used as the label name.
NEGATABLE and NONNEGATABLE indicate whether the qualifier can be
negated by adding W to the qualifier name. The default is NEGATABLE;
if you do not specify either NEGATABLE or NONNEGATABLE, "NO" can be
used on the qualifier name to indicate that the qualifier is not present.
PLACEMENT=placement-clause indicates where the qualifier can appear on
the command line. PLACEMENT accepts the following placement clauses:
GLOBAL

Indicates that the qualifier applies to the entire command and
can be placed after the verb or after a parameter. This is the
default; if you do not specify the PLACEMENT clause, the
qualifier will be GLOBAL.

LOCAL

Indicates that the qualifier can appear only after a parameter
value and that it applies only to that parameter.

POSITIONAL

Indicates that the qualifier can appear anywhere on the
command line, but the meaning of the qualifier depends on
the position which it is used in. If the qualifier is used after a
parameter value, it applies only to that parameter. If it is used
after the verb, the qualifier applies to all parameters.

SYNTAX=syntax-name specifies an alternate syntax definition to be invoked
when the qualifier is present. The syntax name must correspond to the name
used in a DEFINE SYNTAX statement. Specify the syntax name as a symbol.

CDU-26

Command Definition
DEFINE SYNTAX

VALUE[(qual-value-clause[,...])] specifies additional characteristics for
the qualifier. When you specify qualifier value clauses, surround the list
in parentheses and separate items with commas. If you do not specify
any qualifier value clauses, then DCL converts letters in qualifier values to
uppercase.
VALUE accepts the following clauses:
DEFAULT=default-string

Specifies a default value to be used if a value
for the qualifier is not explicitly given. The
DEFAULT clause and the REQUIRED clause are
mutually exclusive. Specify the default string
as a character string that does not exceed 95
characters.
Do not use this clause to specify a default
if the value is a keyword; specify keyword
defaults in the DEFINE TYPE statement, and by
using the DEFAULT qualifer clause.

LIST

Indicates that a list of values separated by
commas can be specified for the qualifier.
This list must be enclosed in parentheses and
separated by commas. Note that plus signs
cannot be used to separate items in a list of
qualifier values.

REQUIRED

Indicates that the qualifier must have an
explicitly specified value. No prompting is
performed for a required qualifier value. The
REQUIRED and the DEFAULT clauses are
mutually exclusive.

TYPE=type-name

Gives either a built-in type or the name of a
DEFINE TYPE statement that defines a list of
keywords that can be used with the qualifier.
Specify the type name as a symbol.
See Section 4.3.1 for more information on
built-in types.

ROUTINE routine-name
Names a routine in a user-written program to be invoked when the changed
syntax is used. Use the ROUTINE clause if you will create an object module
from the command definition file.
The routine-name provides the name of the routine to be executed when
CLI$DISPATCH is called. Specify the routine name as a symbol.
If you do not specify a routine, the routine from the primary DEFINE state¬
ment is invoked. If the primary DEFINE statement does not specify a routine,
no default is provided.

CDU-27

Command Definition
DEFINE SYNTAX

EXAMPLES
Q

DEFINE VERB WRITER
IMAGE "WORK:[JONES]WRITER"
QUALIFIER LINE, SYNTAX=LINE
QUALIFIER SCREEN, SYNTAX=SCREEN
DEFINE SYNTAX LINE
IMAGE "WORK:[JONES]LINE"
QUALIFIER NUM
DEFINE SYNTAX SCREEN
IMAGE "WORK:[JONES]SCREEN"
QUALIFIER AUDIT

This example illustrates a command definition file (WRITER.CLD) containing
DEFINE SYNTAX statements that cause syntax changes depending upon the
qualifiers specified in the command line. The verb WRITER invokes a text
editor (WRITER.EXE). However, you can use the SCREEN and the LINE
qualifiers to invoke alternate text editors.
You can add the command definition to your process command table by
issuing the command:
$ SET COMMAND WRITER

Then, you can use the WRITER command to access different text editors. For
example, if you specify the command
$ WRITER/LINE

you invoke the LINE editor instead of the default editor (WRITER). Syntax
redefinition is done from left to right because parsing of the line is done
from left to right. This order means that when you specify two qualifiers that
invoke different syntax lists, the leftmost qualifier takes precedence (since it is
parsed first).
B

DEFINE VERB DISPLAY
PARAMETER PI, LABEL=ITEM, VALUE(REQUIRED, TYPE=$FILE)
QUALIFIER SAVE. SYNTAX=SAVE
DEFINE SYNTAX SAVE
IMAGE "WORK:[NEWMAN]:SAVE.DISPLAY"
PARAMETER PI. LABEL=ITEM, VALUE(REQUIRED, TYPE=$FILE)
PARAMETER P2, LABEL=NAME

This example shows a syntax change that defines an additional parameter.
The command definition file defines the verb DISPLAY. If the DISPLAY
command is used without the qualifier /SAVE, then one parameter is re¬
quired. This parameter indicates the name of the file to be displayed. If the
DISPLAY command is used with the qualifier /SAVE, then two parameters
are required: the name of the file to be displayed, and the name of the file
where the display should be saved. Note that you must repeat the definition
of PI in the DEFINE SYNTAX statement.

CDU-28

Command Definition
DEFINE TYPE

DEFINE TYPE
Describes the syntax of the keywords that are referenced by the
VALUE(TYPE=type-name) clause. You can use the VALUE clause
in a DEFINE VERB, DEFINE SYNTAX, or DEFINE TYPE statement
to indicate predefined values (keywords) for command parameters,
qualifiers, or keywords.

FORMAT

DEFINE TYPE name[type-clause[,...]]
name
The name of the DEFINE TYPE statement. This name must match the name
used in the VALUE(TYPE=type-name) clause that references the DEFINE
TYPE statement.

type-clause[f...]
Defines a keyword that can be used as the value of the entity that referenced
the DEFINE TYPE statement. The DEFINE TYPE statement accepts the
following type clause:

KEYWORD keyword-name [,keyword-clause[,...]]
Specifies a keyword that may be used as the value of the entity that refer¬
enced the DEFINE TYPE statement. Repeat the KEYWORD type clause for
each keyword that may be used. You can specify up to 255 keywords in a
DEFINE TYPE statement.
The keyword-name is the name of the keyword. The keyword-clause
specifies additional characteristics for the keyword. The use of keyword
clauses is optional.
You can use the following keyword clause:
•

DEFAULT

•

LABEL=label-name

•

NEGATABLE, NONNEGATABLE

•

SYNTAX=syntax-name

•

V ALUE[(key-value-clause[,...])]

DEFAULT indicates that the keyword is present by default. In order for this
keyword to be recognized as present by default, then the parameter, qualifier,
or keyword definition that references this DEFINE TYPE statement must also
specify the DEFAULT clause.
LABEL=label-name defines a label for referencing the keyword at run time.
Specify the label name as a symbol. If you do not specify a label name, the
keyword name is used as the label name.
NEGATABLE and NONNEGATABLE indicate whether the keyword can be
negated by adding "NO" to the keyword name. The default is NONNEGAT¬
ABLE; if you do not specify either NEGATABLE or NONNEGATABLE, "NO"
cannot be used to negate the keyword name. Note that this differs from
qualifiers, which by default, are negatable.

CDU-29

Command Definition
DEFINE TYPE

SYNTAX=syntax-name specifies an alternate verb definition to be invoked
when the keyword is present. The syntax name must match the name used
in the corresponding DEFINE SYNTAX statement. Specify the syntax name
as a symbol.
VALUE[(key-value-clause[,...])] specifies additional characteristics for the
keyword. VALUE accepts the following value clauses:
DEFAULT=default-string

Specifies a default value to be used if a value
for the keyword is not explicitly given. The
DEFAULT clause and the REQUIRED clause
are mutually exclusive. Specify the default
string as a character string that does not
exceed 95 characters.
Do not use this clause to specify a default
if the value is a keyword; specify keyword
defaults in the DEFINE TYPE statement, and
by using the DEFAULT clause with the entity
that uses the keyword.

LIST

Indicates that a list of values for the keyword
may be given. This list must be enclosed in
parentheses and separated by commas. Note
that plus signs may not be used to separate
items in a list of keyword values.

REQUIRED

Indicates that the keyword must have an
explicitly specified value. No prompting is
performed for a required keyword value. If
the keyword is specified without a value, an
error is automatically issued by DCL. The
REQUIRED clause and the DEFAULT clause
are mutually exclusive.

TYPE=type-name

Gives either a built-in type or the name
of a DEFINE TYPE statement that defines
keywords that can be specified as values for
the keyword. The TYPE clause cannot be
specified if the DEFAULT clause is specified.
Specify the type name as a symbol.
See Section 4.3.1 for more information on
built-in types.

EXAMPLES
Q

DEFINE VERB DISPLAY
PARAMETER PI. LABEL=OPTION, PROMPT="What"
VALUE(REQUIRED. TYPE=DISPLAY_OPTIONS)
DEFINE TYPE DISPLAY.OPTIONS
KEYWORD ANIMALS, SYNTAX=DISPLAY.ANIMALS
KEYWORD FLOWERS. SYNTAX=DISPLAY_FLOWERS
DEFINE SYNTAX DISPLAY.ANIMALS
IMAGE "USER:[JOHNSON]ANIMALS"
PARAMETER PI, LABEL=OPTION, VALUE(REQUIRED)
QUALIFIER SMALL
QUALIFIER LARGE
QUALIFIER ALL, DEFAULT
DEFINE SYNTAX DISPLAY.FLOWERS
IMAGE "USER:[JOHNSON]FLOWERS"
PARAMETER PI, LABEL=OPTION, VALUE(REQUIRED)
NOQUALIFIERS

CDU-30

Command Definition
DEFINE TYPE

This example shows how to define keywords that can be specified as param¬
eters for the verb DISPLAY. Each keyword uses its own syntax definition to
invoke an image to execute the command.
After you add the command definition for DISPLAY to your process com¬
mand table, you can issue the following DISPLAY commands:
$ DISPLAY ANIMALS
$ DISPLAY FLOWERS

In addition, the syntax definition DISPLAY—ANIMALS specifies three qual¬
ifiers that can be used only with the command DISPLAY ANIMALS. No
qualifiers are allowed with the command DISPLAY FLOWERS.
2

DEFINE VERB DRAW
QUALIFIER COLOR, TYPE=COLOR_NAMES
DEFINE TYPE COLOR.NAMES
KEYWORD RED
KEYWORD BLUE

This example shows a verb definition that uses a DEFINE TYPE statement
to define keywords that can be used with a qualifier. After you add the
command definition for DRAW to your process command table, you can issue
the following DRAW commands:
$ DRAW/COLOR=RED
$ DRAW/C0L0R=BLUE
0

DEFINE VERB RANDOM
PARAMETER PI, VALUE(TYPE=THINGS), DEFAULT
DEFINE TYPE THINGS
KEYWORD NUMBER, DEFAULT
KEYWORD LETTER

This example defines a verb, RANDOM. RANDOM accepts a parameter,
which must be one of the user-defined keywords NUMBER or LETTER. If
a parameter is not specified with the verb RANDOM, then the default is
NUMBER.
Note that in order for the keyword NUMBER to be present by default, you
must use the DEFAULT clause in two places. You must specify DEFAULT
when you define the parameter in the DEFINE VERB statement. You must
also specify DEFAULT when defining the NUMBER keyword in the DEFINE
TYPE statement.

CDU-31

Command Definition
DEFINE VERB

DEFINE VERB
Defines a new command and specifies information about the pa¬
rameters and qualifiers that can be used with the command. The
DEFINE VERB statement also specifies the image or routine that is
invoked by the newly defined command.

FORMAT

DEFINEVERB verb-name[verb-clause[,...]]
verb-name
The name of the command verb. The verb name is required and must
immediately follow the DEFINE VERB statement. The first four characters of
the verb name must be unique.

verb-dause[,...]
Specify optional verb clauses that define attributes of the command string.
DEFINE VERB accepts the following verb clauses:
•

DISALLOW, NODISALLOWS

•

IMAGE

•

PARAMETER, NOPARAMETERS

•
•
•

QUALIFIER, NOQUALIFIERS
ROUTINE
SYNONYM

These clauses are described below.

IMAGE image-string
Names an image to be invoked by the command. The image-string is
the file specification of the image that DCL invokes when you issue the
command. If you do not provide a complete file specification, the command

CDU-32

Command Definition
DEFINE VERB

language interpreter supplies a default device and directory specification of
SYS$SYSTEM: and a default file type of EXE. Specify the image string as a
character string that does not exceed 63 characters.
If you do not specify the IMAGE verb clause (and you use SET
COMMAND/REPLACE to process the command definition file) the verb
name is used as the image name. At run time, DCL searches for an image
whose file name is the same as the verb name and whose device and directory
names and file type are SYS$SYSTEM: and EXE, respectively.

PARAMETER param-name [,param-clause[,...]]
NOPARAMETERS
Specifies whether parameters can be included in the command string. You
can use the PARAMETER clause up to eight times in a DEFINE VERB
statement. The NOPARAMETERS clause indicates that no parameters are
allowed.
The param-name is the position of the parameter in the command string. The
position must be in the form Pn, where n is the position of the parameter.
The parameter names must be numbered consecutively from PI to P8. The
name must immediately follow the PARAMETER clause.
The param-clause specifies additional chacteristics for the parameter. You
can use the following parameter clauses:
•

DEFAULT

•

LABEL=label-name

•

PROMPT=prompt-string

•

VALUE[(param-value-clause[,...])]

DEFAULT indicates that a user-defined parameter keyword is present by
default. You should use this clause only if you also use the VALUE clause to
indicate that a user-defined keyword must be specified as the parameter value.
See the description of the DEFINE TYPE statement for more information on
defining a keyword that is present by default.
To indicate a default parameter that is not a keyword, use the
VALUE(DEFAULT=default-string) clause.
LABEL=label-name defines a label for referring to a parameter at run time.
Specify the label name as a symbol. If you do not specify a label name, the
parameter name (PI through P8) is used as the label name.
PROMPT=prompt-string supplies a prompt string for a parameter that is not
entered in the command string. If you do not specify a prompt string and
a required parameter is missing, DCL will use the parameter name as the
prompt string. Specify the prompt string as a character string that does not
exceed 31 characters.
If you define more than one parameter and the first parameter is required but
the other parameters are optional, then prompting is done in the following
way. If the user types the command without any parameters, DCL will
prompt for the first (required) parameter until the user types a value, or
aborts the command with a CTRL/Z.

CDU-33

Command Definition
DEFINE VERB

After the user types a value for PI, DCL will prompt for subsequent parame¬
ters, even though these parameters are optional. After the prompt, if the user
types a CTRL/Z, the command is aborted. If the user presses the return key
without entering a value, the command is executed. If the user types a value,
then DCL prompts for the next optional parameter.
VALUE[(param-value-clause[,...])] specifies additional characteristics for
the parameter. When you specify parameter value clauses, enclose them in
parentheses and separate items with commas.
VALUE accepts the following parameter value clauses:
CONCATENATE

Indicates that a parameter can be concate¬
nated to another parameter with a plus
sign.

DEFAULT=default-string

Specifies a default value to be used in the
absence of an explicit parameter value.
The DEFAULT clause and the REQUIRED
clause are mutually exclusive. Specify the
default string as a character string that
does not exceed 95 characters.
Do not use this clause to specify a default
if the value is a keyword; specify keyword
defaults in the DEFINE TYPE statement,
and by using the DEFAULT parameter
clause.

LIST

Indicates that a list of parameters sep¬
arated by commas or plus signs can be
specified.

NOCONCATENATE

Indicates that the parameter cannot be
concatenated to another parameter with a
plus sign.

REQUIRED

Indicates that the parameter is required.
All required parameters must precede
optional ones. If you use the REQUIRED
clause, you should also specify a prompt
string.
The REQUIRED clause and the DEFAULT
clause are mutually exclusive.

TYPE=type-name

Gives either a built-in type or the name of
a DEFINE TYPE statement that defines a
list of keywords that can be specified for
the parameter. Specify the type name as
a symbol.
See Section 4.3.1 for more information on
built-in types.

QUALIFIER qual-name [,qual-clause[,...]]
NOQUALIFIERS
Specifies a qualifier that can be included in the command string. You can use
the QUALIFIER clause up to 255 times in a DEFINE VERB statement. The
NOQUALIFIERS clause indicates that no qualifiers are allowed.
The qual-name is the name of the qualifier. Specify the qualifier name as a
symbol. The first four characters of the qualifier name must be unique.

CDU-34

Command Definition
DEFINE VERB

The qual-clause specifies additional qualifier characteristics. You can use the
following qualifier clauses:
•

BATCH

•

DEFAULT

•

LABEL=label-name

•

NEGATABLE, NONNEGATABLE

•

PLACEMENT=placement-clause

•

SYNTAX=syntax-name

•

VALUE[(qual-value-clause[,...])]

BATCH indicates that the qualifier is present by default if the command is
used in a batch job.
DEFAULT indicates that the qualifier is present by default in both batch and
interactive jobs.
LABEL=label-name defines a label for requesting information about the
qualifier at run time. Specify the label name as a symbol. If you do not
specify a label name, the qualifier name is used as the label name.
NEGATABLE and NONNEGATABLE indicate whether the qualifier can be
negated by adding "NO" to the qualifier name. The default is NEGATABLE;
if you do not specify either NEGATABLE or NONNEGATABLE, "NO" can be
used on the qualifier name to indicate that the qualifier is not present.
PLACEMENT=placement-keyword indicates where the qualifier can appear
on the command line. PLACEMENT accepts the following placement clauses:
GLOBAL

Indicates that the qualifier applies to the entire command and can
be placed after the verb or after a parameter. This behavior is
the default; if you do not specify the PLACEMENT clause, the
qualifier will be GLOBAL.

LOCAL

Indicates that the qualifier can appear only after a parameter, and
applies only to that parameter.

POSITIONAL

Indicates that the qualifier can appear anywhere on the command
line, but its meaning depends on the position it is used in. If
the qualifier is used after a parameter, it applies only to that
parameter. If it is used after the verb, the qualifier applies to all
parameters.

SYNTAX=syntax-name specifies an alternate syntax definition to be invoked
when the qualifier is present. This alternate syntax is useful for commands
that invoke different images depending upon the particular qualifiers that are
present. The syntax name must correspond to the name used in a DEFINE
SYNTAX statement. Specify the syntax name as a symbol.
VALUE[(qual-value-clause[,...])] specifies additional characteristics for
the qualifier. When you specify qualifier value clauses, surround the list
in parentheses and separate items with commas. If you do not specify
any qualifier value clauses, the DCL converts letters in a qualifier value to
uppercase.

CDU-35

Command Definition
DEFINE VERB

VALUE accepts the following clauses:
DEFAULT=default-string

LIST

REQUIRED

Indicates that the qualifier must have an
explicitly specified value. No prompting is
performed for a required qualifier value. The
REQUIRED clause and the DEFAULT clause are
mutually exclusive.

TYPE=type-name

ROUTINE routine-name
Names a routine in a user-written program to be invoked when the command
is issued. Use the ROUTINE clause if you will create an object module from
the command definition file.
The routine-name provides the name of a routine that is executed when
CLI$DISPATCH is called. Specify the routine name as a symbol.
If you do not specify a routine, no default is provided.

SYNONYM synonym-name
Defines a synonym that can be used in place of the verb name. Specify the
synonym-name as a symbol.

EXAMPLES
Q

DEFINE VERB ERASE
PARAMETER,PI VALUE(DEFAULT=DISK3:[JONES]STATS.DAT)

This definition tells the command language interpreter that erase is a valid
verb and that it takes a parameter. If the user does not enter a parameter
value, the default is DISK3:[JONES]STATS.DAT.
Because no image name is specified, the verb ERASE invokes the image
SYS$SYSTEM:ERASE.EXE.

CDU-36

Command Definition
DEFINE VERB

DEFINE VERB SCATTER
IMAGE "WRKD$:[MORRISON]SCATTER"
PARAMETER PI, LABEL=INFILE, PROMPT="Input_file?", VALUE(REQUIRED)
PARAMETER P2, LABEL=OUTFILE, PROMPT="Output_file?", VALUE(REQUIRED)
QUALIFIER SLOW, DEFAULT
QUALIFIER FAST
DISALLOW SLOW AND FAST

This example shows a command definition file which defines a new
command, called SCATTER. The new command will invoke the image
WRKD$:[MORRISON] SCATTER.EXE. It has two required parameters, an
input file and an output file. It also has two qualifiers, /SLOW and /FAST.
If you do not explicitly specify any qualifiers, /SLOW is present by default.
You cannot specify both /SLOW and /FAST on the same command line.

CDU-37

Command Definition
IDENT

IDENT
Provides identifying information for an object module that is created
from a command definition file.

FORMAT

IDENT ident-string
ident-string
A string which contains identifying information. Specify the ident-string as a
character string that does not exceed 31 characters.

EXAMPLE
MODULE COMMAND.TABLE
IDENT "V04-001"
DEFINE VERB SPIN

This command definition file uses the IDENT statement to identify the file.

CDU-38

Command Definition
MODULE

MODULE
Creates a symbolic name for an object module that is created from a
command definition file.

FORMAT

MODULE module-name
module-name
Symbolic name for the object module. This name refers to the address where
the linker locates a command table module that is linked with a user-written
program.
If you do not specify a module name, the CDU uses the object file name
(specified with the /OBJECT command qualifier) as the default module name.
If no object file is explicitly specified, then the CDU uses the name of the first
command definition file as the module name.

EXAMPLE
$ CREATE TEST.CLD
MODULE TEST.TABLE
DEFINE VERB SEND
ROUTINE SEND.ROUT
PARAMETER PI

DEFINE VERB SEARCH
ROUTINE SEARCH.ROUT
PARAMETER PI
$ SET COMMAND/OBJECT=TEST.OBJ TEST
$ LINK PROG,TEST
$ RUN PROG

This example shows a command definition file, TEST.CLD, which defines
two commands, SEND and SEARCH. These commands invoke routines in
the program PROG.EXE. PROG.EXE is a user-written program that accepts
command strings and uses DCL to parse these strings and execute routines.
The SET COMMAND command is used to create an object module which
contains a command table for the SEND and SEARCH commands. When
the object module for the program (PROG.OBJ) is linked with the object
module for the command table (TEST.OBJ) the resulting image (PROG.EXE)
contains the code for the program and command table. The symbolic name
TEST-TABLE refers to the address in the image where the command table is
located.
When you run PROG.EXE, it will call DCL parsing routines to parse the
command string using the command table at module TEST—TABLE.

CDU—39

Command Definition
Command Qualifiers

COMMAND
QUALIFIERS

The following pages describe the qualifiers that can be used with the DCL
command SET COMMAND to invoke the Command Definition Utility. The
qualifiers are
•

/DELETE

•

/LISTING

•

/OBJECT

•

/OUTPUT

•

/REPLACE

•

/TABLE

The /DELETE, /OBJECT, and /REPLACE qualifiers indicate SET
COMMAND modes; these qualifiers are mutually exclusive.

CDU—40

Command Definition
/DELETE

/DELETE
Specifies /DELETE mode to delete verb or synonym names from the
command table you are modifying. If a verb name has synonyms,
the /DELETE qualifier deletes the specified verb or synonym name.
If any synonyms remain, or if you delete synonyms and the original
verb name remains, the remaining names can still reference the verb
definition.
You can use the /DELETE qualifier to delete a verb in either your
process command table or in a command table file specified with
the /TABLE qualifier. If you do not use the /TABLE qualifier to
specify an alternate command table, the default is to delete verbs
from your process command table. If you do not use the /OUTPUT
qualifier to specify an output file, the default is to return the modified
command table to your process.
You cannot use the /LISTING, /OBJECT, or /REPLACE qualifiers
with /DELETE.

FORMAT

SET COMMAND/DELETE= (verb[,...])
verb
A verb or verb synonym to be deleted from the specified command table. If
you specify two or more names, separate them with commas and enclose the
list in parentheses.

EXAMPLES
Q

$ SET COMMAND/DELETE=DO

In this example, SET COMMAND deletes the definition for the command DO
from your process command table.
g

SET COMMAND/DELETE=(PUSH,SHOVE)/TABLE=TEST_TABLE/OUTPUT=NEW_TABLE

The commands PUSH and SHOVE are deleted from the command table
TEST_TABLE.EXE. The /OUTPUT qualifier writes the modified table to the
file NEW_TABLE.EXE. If you did not include the /OUTPUT qualifier, the
modified table would have been written to your process, and would have
overwritten the commands in your process command table.

CDU-41

Command Definition
/LISTING

/LISTING
Controls whether an output listing is created and optionally provides
an output file specification for the listing file. A listing file contains
a listing of the command definitions along with any error messages.
The listing file is similar to a compiler listing.
If you specify the /LISTING qualifier and omit the file specification,
output is written to the default device and directory; the listing file
will have the same name as the first command definition file and a
file type of LIS.
You can use the /LISTING qualifier only in /OBJECT or /REPLACE
mode; you cannot create a listing in /DELETE mode. In /OBJECT
and /REPLACE modes, the default is /NOLISTING.

FORMAT

SET COMMAND/[NO]LISTING [=listing-file-spec]
[file-specf,...]]
listing-file-spec
The file specification for the listing file. If no file name is specified, the name
will default to the name of the first command definition file. The default file
type is LIS.

file-spec
The name of the command definition file to be processed. The default file
type is CLD. Wildcard characters are allowed in the file specification.

EXAMPLES
□

$ SET COMMAND/LISTING TEST

In this example, the command definition file TEST.CLD is processed by the
CDU, and the new verbs are added to your process command table. (By
default, SET COMMAND uses /REPLACE mode.) The modified table is
returned to your process, and a listing file named TEST.LIS is created.
0

$ SET COMMAND/LISTING=A TEST

The command definition file TEST.CLD is processed by the CDU, and the
verb definitions are added to your process command table. The modified
table is returned to your process, and a listing file named A.LIS is created.
E

$ SET COMMAND/LISTING/OBJECT GAMES

SET COMMAND is used to create an object module (GAMES.OBJ) that
contains the command definitions in GAMES.CLD. The object module can
be linked with a user-written program. A listing file named GAMES.LIS is
created.

CDU—42

Command Definition
/OBJECT

/OBJECT
Specifies /OBJECT mode to create an object module from a com¬
mand definition file and, optionally, provides an object file specifi¬
cation. You cannot use the /OBJECT qualifier to create an object
module from a command definition that contains the IMAGE clause.
An object module containing a command table can be linked with
the object modules from a user-written program. The program can
then use its own command table to parse command strings and
execute routines.
You can specify only one command definition file when you use SET
COMMAND/OBJECT.
If you specify the /OBJECT qualifier and omit the file specification,
output is written to the default device and directory; the object file
will have the same name as the input file and a file type of OBJ.
You cannot use the /DELETE, /OUTPUT, /REPLACE, or /TABLE
qualifiers with /OBJECT.

FORMAT

SET COMMAND/OBJECT [=object-file-spec]
file-spec
object- file-spec
The file specification for the object file. If no file name is specified, it will
default to the name of the first input (command definition) file. The default
file type is OBJ.

file-spec
The name of the command definition file to be processed. The default file
type is CLD. Wildcard characters are allowed in the file specification.

EXAMPLES
Q

$ SET COMMAND/OBJECT TEST

In this example, the command definition file TEST.CLD is processed and a
new command table is created. This table is written as an object module to a
file named TEST.OBJ. (The name of the object module, if not explicitly given,
defaults to the name of the command definition file, with a file type of OBJ.)
0

$ SET COMMAND/OBJECT=A TEST

In this example, the command definition file TEST.CLD file is processed and
the command table is written as an object module to a file named A.OBJ.

CDU-43

Command Definition
/OUTPUT

/OUTPUT
Controls where the modified command table should be placed. If
you provide an output file specification, the modified command
table is written to the specified file. If you do not provide an output
file specification, the modified command table is placed in your
process. The /NOOUTPUT qualifier indicates that no output is to be
generated.
You can use the /OUTPUT qualifier only in /DELETE or /REPLACE
mode; the default is /OUTPUT with no file specification. You cannot
use the /OUTPUT qualifier in /OBJECT mode.

FORMAT

SET COMMAND/OUTPUT [=output-file-spec]
[file-spec[r... ]]
SET COMMAND/NOOUTPUT
output-file-spec
The file specification of the output file which contains the edited command
table. The default file type is EXE.
You can specify an output file only when you also use the /TABLE=file-spec
qualifier to provide the input table.

file-spec
The name of the command definition file to be processed. The default file
type is CLD. Wildcard characters are allowed in the file specification.

EXAMPLES
Q

$ SET COMMAND/OUTPUT TEST

The file TEST.CLD is processed and the definitions are added to your process
command table. The modified table is returned to your process. (The result is
the same as if you had issued the command SET COMMAND TEST.)
2

$ SET COMMAND/TABLE=A/OUTPUT=A TEST

The definitions from the file TEST.CLD are added to the command table
A.EXE. The modified table is written to a new file named A.EXE with a
version number one greater than the number of the input table file.
If you use the /TABLE qualifier to provide an input command table, be sure
to provide an output file specification. Otherwise, the modified command
table will be written to your process and will replace your process command
table.
g

$ SET COMMAND/NOOUTPUT TEST

The definitions from TEST.CLD are added to your process command table,
and the modified table is not written anywhere. You can use this command
string to test whether a command definition file is written correctly.

CDU-44

Command Definition
/REPLACE

/REPLACE
Specifies /REPLACE mode to add or replace verbs in the command
table you are modifying.
You can use the /REPLACE qualifier to modify either the process
command table or a command table file specified with the /TABLE
qualifier. If you do not use the /TABLE qualifier to specify an alter¬
nate command table, the default is to modify your process com¬
mand table. If you do not use the /OUTPUT qualifier to specify an
output file, the default is to return the modified command table to
your process.
You cannot use the /OBJECT or /DELETE qualifiers in /REPLACE
mode.
If you do not explicitly specify /DELETE, /OBJECT, or /REPLACE,
the default is /REPLACE.

FORMAT

SET COMMAND/REPLACE [file-spec[,...]]
file-spec
The name of the command definition file to be processed. The default file
type is CLD. Wildcard characters are allowed in the file specification.

EXAMPLES
Q

$ SET COMMAND SCROLL

This command adds the command definitions from the file SCROLL.CLD to
your process command table. The /REPLACE, /TABLE, and /OUTPUT qual¬
ifiers are present by default. The /REPLACE qualifier indicates /REPLACE
mode; the /TABLE qualifier indicates that your process command table is to
be modified; the /OUTPUT indicates that the modified command table is to
be written to your process.
S

$ SET COMMAND/TABLE/OUTPUT SCROLL

This command adds the command definitions from the file SCROLL.CLD to
your process command table, and returns the modified table to your process.
(The /TABLE and /OUTPUT qualifiers, with no specified files, default to
your process command table.) This command is the same as the command
SET COMMAND SCROLL.
B

$ SET COMMAND/TABLE=COMMAND_TABLE/OUTPUT=NEW_TABLE TEST

In this example the command definitions from the file TEST.CLD are added
to the command table in the file COMMAND_TABLE.EXE. The modified
command table is written to the file NEW_TABLE.EXE.
If you use the /TABLE qualifier to provide an input command table, be sure
to provide an output file specification. Otherwise, the modified command
table will be written to your process and will replace your process command
table.

CDU-45

Command Definition
/REPLACE

$ SET COMMAND/TABLE=TEST_TABLE MYCOMS

In this example, the definitions from MYCOMS.CLD are added to the com¬
mand table in TEST_TABLE.EXE. The modified command table is written to
your process and replaces your process command table. You should replace
your process command table only if the new command table contains all
the commands you need to perform your work; the DCL commands that
were copied to your process command table when you logged in will be
overwritten.

CDU—46

Command Definition
/TABLE

/TABLE
Specifies the command table that is to be modified. If you specify
the /TABLE qualifier and omit the file specification, the current pro¬
cess command table is modified. If you include a file specification,
the specified command table is modified. The default file type is
EXE.
If you use the /TABLE qualifier to provide an input table file, you
should also use the /OUTPUT qualifier to provide an output table
file. Otherwise, the modified command table will be written to your
process and will replace your process command table.
You can use the /TABLE qualifier in /DELETE or /REPLACE mode;
the default is /TABLE with no input file specification. You cannot
use the /TABLE qualifier in /OBJECT mode.

FORMAT

SET COMMAND/TABLE [=input-file-spec]
[file-spec [,...]]

SET COMMAND/NOTABLE
input-file-spec
The file specification of the input file which contains the command table to be
edited. The default file type is EXE.

file-spec
The name of the command definition file to be processed. The default file
type is CLD. Wildcard characters are allowed in the file specification.

EXAMPLES
Q

$ SET COMMAND/TABLE TEST

The commands from TEST.CLD are added to your process command table,
and the results are returned to your process. The /TABLE qualifier with no
file specification indicates that your process command table is to be modified.
This command is the same as the command SET COMMAND TEST.
Q

$ SET COMMAND/TABLE=A/OUTPUT=B TEST

In this example the command definitions from the file TEST.CLD are added to
the command table in the file A.EXE. The modified command table is written
to the file B.EXE.
If you use the /TABLE qualifier to provide an input command table, be sure
to provide an output file specification. Otherwise, the modified command
table will be written to your process and will replace your process command
table.

CDU—47

Command Definition
/TABLE

$ SET COMMAND/TABLE=A

In this example, the command table in A.EXE is written to your process
and replaces your process command table. You should replace your process
command table only if the new command table contains all the commands
you need to perform your work; the DCL commands that were copied to your
process command table when you logged in will be overwritten.

CDU—48

Command Definition
Examples

COMMAND
DEFINITION
UTILITY
EXAMPLES
Adding a Command to Your Process Command Table
This example shows how to add a command to your process command table,
and how to use command language routines in the image invoked by the new
command.
The following command definition file defines a new verb, called SAMPLE.
DEFINE VERB SAMPLE
IMAGE "USERDISK:[MYDIR]SAMPLE"
PARAMETER PI,LABEL=FILESPEC
QUALIFIER EDIT

To process this command definition file, use the DCL command SET
COMMAND:
$ SET COMMAND SAMPLE

This command string invokes the CDU to process the command definition file
(SAMPLE.CLD) and add the verb SAMPLE to your process command table.
The modified table is returned to your process.
The following program illustrates a program called SAMPLE.BAS. It uses the
CLI$PRESENT and CLI$GET_VALUE command language routines to obtain
information about a command string parsed by DCL.
1

EXTERNAL INTEGER FUNCTION CLI$PRESENT,CLI$GET_VALUE

IF CLI$PRESENT('EDIT') AND 1%
THEN
PRINT '/EDIT IS PRESENT',A$

IF CLI$PRESENT('FILESPEC') AND 1%
THEN
CALL CLI$GET_VALUE('FILESPEC',A$)
PRINT 'FILESPEC = ',A$

END

This source program must be compiled and linked before it can be invoked by
a command verb. When you have finished compiling and linking the source
program you will have created a file called SAMPLE.EXE, which contains an
executable image.
You can now use the SAMPLE command to invoke the image SAMPLE.EXE,
as shown below:
$ SAMPLE

DCL processes this command in the same way it processes the
DIGITAL-supplied DCL commands; that is, DCL checks the syntax and then
invokes SAMPLE.EXE to execute the command.
You may include in the command string any parameters and qualifiers
defined for the SAMPLE command verb. For example, you can then enter the
following command string:
$ SAMPLE MYFILE

In this case, you will receive the following display on your screen:
FILE-SPEC = MYFILE

CDU—49

Command Definition
Examples

You can also include the /EDIT qualifier in the command string. For example:
$ SAMPLE MYFILE/EDIT

In this case, you will receive the following display on your screen:
/EDIT IS PRESENT
FILE-SPEC = MYFILE

If you include a qualifier that is not accepted by the command verb, you will
receive a DCL error message. For example:
$ SAMPLE MYFILE/UPDATE
%DCL-W-IVQUAL, unrecognized qualifier - check validity, spelling, and placement
\UPDATE\

If you include two or more parameters in the command string for a verb
that was defined to accept only one parameter, you will also receive an error
message. For example:
$ SAMPLE MYFILE INFILE
%DCL-W-MAXPARM, too many parameters - reenter command with fewer parameters
\INFILE\

Creating an Object Module Table for a User-Written Program
This example shows how to create an object module table for a user-written
program. It also shows how to use command language routines to parse a
command string and invoke the correct program routine.
When you write a command definition file from which you will create an
object module, specify routines (not images) for each command verb. These
routines will be called by your program when it processes command strings.
The following example illustrates a command definition file called TEST.CLD
that contains the names of three verbs: SEND, SEARCH, and EXIT. Each
verb invokes a routine in the program USEREXAMP.BAS.
MODULE TEST.TABLE
DEFINE VERB SEND
ROUTINE SEND.COMMAND
PARAMETER PI, LABEL = FILESPEC
QUALIFIER EDIT
DEFINE VERB SEARCH
ROUTINE SEARCH.COMMAND
PARAMETER PI, LABEL = SEARCH.STRING
DEFINE VERB EXIT
ROUTINE EXIT.COMMAND

Process TEST.CLD by using SET COMMAND with the /OBJECT qualifier to
create an object module named TEST.OBJ. For example:
$ SET COMMAND/OBJECT TEST

Design a program to invoke the routines listed in the command table in
TEST.OBJ. You can then link TEST.OBJ with an object module that was
created from your user source program.
The following program, entitled USEREXAMP.BAS, is written in BASIC. It
uses the command language routines CLI$DCL_PARSE and CLI$DISPATCH
to parse command strings and invoke the routine associated with the com¬
mand. The program also uses CLI$PRESENT and CLI$GET_VALUE to
obtain information about command strings.

CDU-50

IF CLI$PRESENT ('EDIT') AND 1%
THEN
PRINT '/EDIT IS PRESENT'

IF CLISPRESENT ('FILESPEC') AND 17.
THEN
CALL CLI$GET_VALUE ('FILESPEC',A$)
PRINT 'FILE.SPEC = ',A$

SUBEND

100 SUB SEARCH.COMMAND
EXTERNAL INTEGER FUNCTION CLI$PRESENT,CLI$GET_VALUE
PRINT
PRINT

'SEARCH COMMAND'
''

110 IF CLISPRESENT ('SEARCH.STRING') AND 17.
THEN
CALL CLI$GET_VALUE('SEARCH.STRING',A$)
PRINT 'SEARCH.STRING = ',A$
190 SUBEND
200 SUB EXIT.COMMAND
EXTERNAL INTEGER FUNCTION SYS$EXIT
CALL SYS$EXIT(17.)
290 SUBEND
1

EXTERNAL INTEGER FUNCTION CLI$DCL_PARSE,CLI$DISPATCH,LIB
EXTERNAL INTEGER FUNCTION SEND.COMMAND,SEARCH.COMMAND,E
EXTERNAL INTEGER TEST.TABLE

IF NOT CLI$DCL_PARSE(0,TEST.TABLE,LIBSGET.INPUT,LIBSGE
THEN

PRINT ''
CALL CLISDISPATCH

GOTO 2

GOTO 2
END

This source program must be compiled before it can be
module created from the SET COMMAND/OBJECT co
this program, invoke the VAX BASIC compiler as show
$ BASIC USEREXAMP

You now have a USEREXAMP.OBJ file in addition to t
AMP.BAS source file. Link USEREXAMP.OBJ with TES
DCL command
$ LINK USEREXAMP,TEST

You now have a file containing an executable image (U
execute the image, use the DCL command
$ RUN USEREXAMP

USEREXAMP.EXE displays the following prompt on yo
TEST>

You can now enter any of the commands you defined
example:
TEST> SEND

Command Definition
Examples

The program calls CLI$DCL_PARSE to parse the command string SEND.
SEND is a valid command, so CLI$DISPATCH transfers control to the
SEND—COMMAND routine. This routine displays the following text on your
screen:
SEND COMMAND
TEST>

You can also include a parameter with the SEND command. For example:
TEST> SEND MESSAGE.TXT

The SEND—COMMAND routine will be invoked again and it will display the
following text on your screen:
SEND COMMAND
FILE.SPEC = MESSAGE.TXT
TEST>

You can also enter the /EDIT qualifier with SEND. For example:
TEST> SEND/EDIT MESSAGE.TXT
SEND COMMAND
/EDIT is present
FILE-SPEC = MESSAGE.TXT
TEST>

You can enter other commands that your program accepts. For example:
TEST> SEARCH

The SEARCH command string invokes a different routine than the one
defined by SEND. In this case, the following text will be displayed on your
screen:
SEARCH COMMAND
TEST>

Unlike the SEND command, the SEARCH command accepts no qualifiers. If
you attempt to include a qualifier (such as /EDIT) in the SEARCH command
string, CLI$DCL_PARSE will signal the following error:
%CLI-W-NOQUAL, qualifier not allowed on this command

To exit from the USEREXAMP program and return to the DCL command
level, issue the EXIT command:
TEST> EXIT

Index

B
BATCH clause
for QUALIFIER clause* CDU-26, CDU-35

Command table (cont'd.)
object module for* CDU-18, CDU-43
output file*CDU-44
process table • CDU-5
system table • CDU-5
CONCATENATE clause
for VALUE clause • CDU-25, CDU-34

D
Character string
See String
Clauses
summary of*CDU-2 to CDU-3
CLISDCI_PARSE • CDU-19, CDU-50
CLI$DISPATCH • CDU-19, CDU-50
CLI$GET_VALUE • CDU-19, CDU-49, CDU-50
CLI$PRESENT *000-19, CDU-49, CDU-50
Command definition file
creation of*CDU-7 to CDU-16
for sample program*CDU-49, CDU-50
processing of*CDU-17 to CDU-19
rules for formatting • CDU-7
statements in*CDU-7, CDU-20 to CDU-39
syntax change definition • CDU-9
verb definition *CDU-8
Command language interpreter
function of*CDU-4
Command language routines *CDU-4
summary of*CDU-19
use of*CDU-49, CDU-50
Command processing
See DCL
Command string
entities in*CDU-4
processing of*CDU-4 to CDU-5
Command table
adding commands to*CDU-6, CDU-17, CDU-45
creating a new table*CDU-18
creating object module for*CDU-6
deleting commands from*CDU-18, CDU-41
input table *CDU-47
listing file for*CDU-42

DCL
command language routines*CDU-19
command processing • CDU-4 to CDU-5
DEFAULT clause
for DEFINE TYPE statement • CDU-29
for PARAMETER clause *CDU-24, CDU-33
for QUALIFIER clause • CDU-26, CDU-35
for VALUE clause • CDU-25, CDU-27, CDU-30,
CDU-34, CDU-36
DEFINE SYNTAX statement*CDU-9, CDU-21 to
CDU-28
DISALLOW clause *CDU-23
IMAGE clause *CDU-24
NODISALLOWS clause • CDU-23
NOPARAMETERS clause*CDU-24
NOQUALIFIERS clause • CDU-26
PARAMETER clause • CDU-24
QUALIFIER clause*CDU-26
ROUTINE clause*CDU-27
table of syntax changes • CDU-21 to CDU-23
DEFINE TYPE statement • CDU-11, CDU-29 to
CDU-31
DEFAULT clause*CDU-29
LABEL clause*CDU-29
NEGATABLE clause • CDU-29
NONNEGATABLE clause • CDU-29
SYNTAX clause*CDU-29
VALUE clause*CDU-30
DEFINE VERB statement • CDU-8, CDU-32 to
CDU-37
DISALLOW clause*CDU-32
IMAGE clause*CDU-32
NODISALLOWS clause • CDU-32

Index—1

Index

DEFINE VERB statement (cont'd.)
NOPARAMETERS clause • CDU-33
NOQUALIFIERS clause *000-34
PARAMETER clause*CDU-33
QUALIFIER clause *CDU-34
ROUTINE clause *CDU-36
SYNONYM clause *CDU-36
Definition path
definition of*CDU-14 to CDU-15
/DELETE qualifier *CDU-41
DISALLOW clause *CDU-11 to CDU-16
definition path*CDU-14
evaluation of*CDU-11
for DEFINE SYNTAX statement *CDU-23
for DEFINE VERB statement • CDU-32
keyword path*CDU-13
operators for*CDU-15 to CDU-16
specifying entities in*CDU-12 to CDU-15

Keyword (cont'd.)
how to define *CDU-11
Keyword path
definition of*CDU-13 to CDU-14

L
LABEL clause
for DEFINE TYPE statement *CDU-29
for PARAMETER clause • CDU-24, CDU-33
for QUALIFIER clause *CDU-26, CDU-35
LIST clause
for VALUE clause • CDU-25, CDU-27, CDU-30,
CDU-34, CDU-36
/LISTING qualifier *CDU-42
LOCAL clause
for PLACEMENT clause* CDU-26, CDU-35

F
Format
for SET COMMAND command • CDU-1

GLOBAL clause
for PLACEMENT clause • CDU-26, CDU-35

i
IDENT statement*CDU-16, CDU-38
IMAGE clause
for DEFINE SYNTAX statement • CDU-24
for DEFINE VERB statement • CDU-32

K
Keyword
See also DEFINE TYPE statement

Index—2

M
MODULE statement • CDU-16, CDU-39

NEGATABLE clause
for DEFINE TYPE statement • CDU-29
for QUALIFIER clause *CDU-26, CDU-35
NOCONCATENATE clause
for VALUE clause*CDU-25, CDU-34
NODISALLOW clause
for DEFINE SYNTAX statement *CDU-23
for DEFINE VERB statement*CDU-32
NONNEGATABLE clause
for DEFINE TYPE statement • CDU-29
for QUALIFIER clause • CDU-26, CDU-35
NOPARAMETERS clause
for DEFINE SYNTAX statement • CDU-24
for DEFINE VERB statement*CDU-33
NOQUALIFIERS clause
for DEFINE SYNTAX statement • CDU-26
for DEFINE VERB statement • CDU-34

Index

Object module
for command table *0011-6, CDU-18, CDU-43
statements for*CDU-16
/OBJECT qualifier*CDU-43

/REPLACE qualifier *CDU-45 to CDU-46
REQUIRED clause
for VALUE clause*CDU-25, CDU-27, CDU-30,
CDU-34, CDU-36
Restriction
for use of CDU*CDU-2
ROUTINE clause
for DEFINE SYNTAX statement • CDU-27
for DEFINE VERB statement • CDU-36

Operators
for DISALLOW clause • CDU-15 to CDU-16
/OUTPUT qualifier *CDU-44

p
Parameter
how to define *CDU-24, CDU-33
PARAMETER clause
for DEFINE SYNTAX statement • CDU-24
for DEFINE VERB statement • CDU-33
PLACEMENT clause
for QUALIFIER clause *CDU-26, CDU-35
POSITIONAL clause
for PLACEMENT clause • CDU-26, CDU-35
Process command table
adding commands to*CDU-6, CDU-49
definition of*CDU-5
deleting commands from*CDU-41
PROMPT clause
for PARAMETER clause*CDU-24, CDU-33

Q
Qualifier
for SET COMMAND command • CDU-40 to
CDU-48
how to define*CDU-26, CDU-34
QUALIFIER clause
for DEFINE SYNTAX statement • CDU-26
for DEFINE VERB statement • CDU-34

s
Sample program
invoked by user-defined command • CDU-49
to parse and execute commands • CDU-50
SET COMMAND command
delete mode*CDU-18, CDU-41
input for*CDU-47
object mode*CDU-18, CDU-43
output from*CDU-44
processing modes*CDU-17
qualifiers for*CDU-40 to CDU-48
replace mode*CDU-17, CDU-45
Statements
for command definition file*CDU-20 to CDU-39
summary of*CDU-2
String
specification of*CDU-7
Symbol
specification of*CDU-7
SYNONYM clause
for DEFINE VERB statement • CDU-36
Syntax change
See also DEFINE SYNTAX statement
how to define *CDU-9
SYNTAX clause
for DEFINE TYPE statement • CDU-29
for QUALIFIER clause • CDU-26, CDU-35
System command table
adding commands to*CDU-6
definition of*CDU-5

Index—3

Index

T
Table
See Command table
/TABLE qualifier •CDU-47 to CDU-48
Type
built-in* CDU-10
TYPE clause
definition of value types •CDU-10
for VALUE clause *CDU-25, CDU-27, CDU-30,
CDU-34, CDU-36

u
Usage summary • CDU-1

v
Value
built-in type*CDU-10
how to define*CDU-10 to CDU-11
user-defined • CDU-11
VALUE clause
for DEFINE TYPE statement • CDU-30
for PARAMETER clause • CDU-25, CDU-34
for QUALIFIER clause *CDU-26, CDU-35
Verb
See also DEFINE VERB statement
how to define *CDU-8

Index—4

VAX/VMS Command
Definition Utility
Reference Manual
AA-Z408A-TE

READER'S
rnMMFNT^S

Note: This form is for document comments only. DIGITAL will use comments
submitted on this form at the company's discretion. If you require a written reply
and are eligible to receive one under Software Performance Report (SPR) service,
submit your comments on an SPR form.

Did you find this manual understandable, usable, and well organized? Please make suggestions for
improvement.

Did you find errors in this manual? If so, specify the error and the page number.

Please indicate the type of user/reader that you most nearly represent:
□
□
□
□
□
□

Assembly language programmer
Higher-level language programmer
Occasional programmer (experienced)
User with little programming experience
Student programmer
Other (please specify) _

Name -DateOrganization ___
Street ___
City ___State_Zip Code_
or Country

- —

—

Do Not Tear - Fold Here and Tape

IflQSD

No Postage
Necessary
if Mailed in the
United States

BUSINESS REPLY MAIL
FIRST CLASS PERMIT NO.33 MAYNARD MASS.
POSTAGE WILL BE PAID BY ADDRESSEE

SSG PUBLICATIONS ZK1-3/J35
DIGITAL EQUIPMENT CORPORATION
110 SPIT BROOK ROAD
NASHUA, NEW HAMPSHIRE 03062-2698

Do Not Tear - Fold Here

#
Cut Along Dotted Line

— —