DEFINE WORK FILE

DEFINE WORK FILE n

operand1 [TYPE operand2]
TYPE operand2

[ATTRIBUTES  {operand3}...]

Note:
The elements shown in square brackets [...] are optional, however, at least one of them must be specified with this statement.

This document covers the following topics:

For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.

Related Statements: CLOSE WORK FILE | READ WORK FILE | WRITE WORK FILE

Belongs to Function Group: Control of Work Files / PC Files

Function

The statement DEFINE WORK FILE is used to assign a file name to a Natural work file number within a Natural application. This allows you to make or change work file assignments dynamically within a Natural session or overwrite work file assignments made at another level. See also Work Files in the Operations documentation.

When this statement is executed and the specified work file is already open, the statement will implicitly close the work file.

Note:
For Unicode and code page support on Windows, UNIX and OpenVMS platforms, see Work Files and Print Files in the Unicode and Code Page Support documentation.

Syntax Description

Operand Definition Table:

Operand Possible Structure Possible Formats Referencing Permitted Dynamic Definition
operand1 C S       A U                     yes no
operand2 C S       A U                     yes no
operand3 C S       A U                     yes no

Note:
If a format U operand is specified in Unicode (UTF-16), it is converted to session code page characters before it is evaluated.

Syntax Element Description:

Syntax Element Description
DEFINE WORK FILE n
Work File Number:

n is the work file number (1 to 32). This is the number to be used in a WRITE WORK FILE, READ WORK FILE or CLOSE WORK FILE statement.

operand1
Work File Name:

operand1 is the name of the work file.

The file name (operand1) may contain environment variables. It is possible to use physical work file names. If a file with the specified name does not exist, it will be created.

If operand1 is not specified, the value of operand1 is determined by taking the work file name stored with the Configuration Utility in the parameter file for the corresponding work file number.

Note:
If operand1 is not specified, the behavior of Natural for Mainframes and Natural for Windows/UNIX/OpenVMS is different.

TYPE operand2
TYPE Clause:

operand2 specifies the type of work file. See also Handling of Large and Dynamic Variables in the description of the WRITE WORK FILE statement.

The value of operand2 is handled in a case insensitive way and must be enclosed in quotes or provided in an alphanumeric variable.

DEFAULT

Determines the file type from the extension.

Format: Depends on the work file type.

Note:
The file type TRANSFER cannot be determined by the work file type DEFAULT. You must explicitly define TRANSFER as the file type you wish to use.

TRANSFER

Is used to transfer data to and from a PC with Entire Connection.

This work file type represents a data connection between a Natural session on UNIX or OpenVMS and an Entire Connection terminal on a PC.

Format: ENTIRE CONNECTION

Notes:

  1. This work file type cannot be used in conjunction with the ATTRIBUTES Clause.
  2. This work file type is not available under Windows.
SAG Format: binary
ASCII

Files in ASCII are "text" files with records terminated by [a carriage return] line feed.

Format: ASCII
ASCII-COMPRESSED

Is a file in ASCII format, with the exception that all trailing blanks are removed.

Format: ASCII
ENTIRECONNECTION

With this work file type, you can read and write (using the statements READ and WRITE, for example) directly from/to a work file in Entire Connection format on the local disc.

Format: ENTIRE CONNECTION

Note:
This work file type is available on PCs, on UNIX and on OpenVMS. No transfer to PC is possible. The Entire Connection terminal is not used in this process.

UNFORMATTED

A completely unformatted file. No formatting information is written (neither for fields nor for records).

Format: UNFORMATTED
PORTABLE

Files which can handle dynamic variables exactly and can also be transported: for example, from a Little Endian machine to a Big Endian machine, and vice versa.

Format: PORTABLE
CSV

Comma-separated values. Each record is written to one line in the file. By default, a header is not written. The default character which is used to separate the data fields is a semicolon (;).

For further information, see Work Files in the Configuration Utility documentation.

ATTRIBUTES {operand3}...
ATTRIBUTES Clause:

operand3 specifies a work file attribute.

Several attributes separated by a comma or a blank can be specified, for example: 

DEFINE WORK FILE ATTRIBUTES 'APPEND,KEEP'

If multiple values for the same attribute type are specified, the last value is taken, for example: 

DEFINE WORK FILE ATTRIBUTES 'APPEND,NOAPPEND'

In this case, NOAPPEND will be taken.

Example for BOM/NOBOM usage: 

...
DEFINE WORK FILE 11 'x.tmp' ATTRIBUTES 'BOM'
*
* write work file with BOM
*
DEFINE WORK FILE 11 'x.tmp' ATTRIBUTES 'NOBOM'
*
* write work file without BOM
...

Note:
If operand3 is omitted, the corresponding value defined in the parameter file, as created by the Configuration Utility, is implicitly used.

The following is an overview of the attribute types and their possible values:

Append Mode:
NOAPPEND Deactivates the append mode. The file is rewritten from the start. This is the default value.
APPEND Activates the append mode. In this mode, new records are added at the end of the file.
Keep/Delete File after Work File Close:
DELETE The work file is deleted after a close work file operation.
KEEP The work file is kept after a close work file operation. This is the default value.
Write Byte Order Mark (BOM):
BOM A byte order mark is written in front of the work file data.

Only available for the work file types which write code page data: ASCII, ASCII-COMPRESSED, UNFORMATTED and CSV. For these work file types, the attribute BOM can only be set, if the code page UTF-8 is defined for the work file (see the description of the TYPE clause).

If a work file of another type is written or a code page other than UTF-8 is defined, the specification of the attribute BOM is ignored during runtime.

See also Work Files and Print Files on Windows, UNIX and OpenVMS Platforms in the Unicode and Code Page Support documentation.

NOBOM No byte order mark is written in front of the work file data. This is the default value.
Remove/Keep Carriage Return:
KEEPCR Carriage return characters are kept when reading an ASCII work file.

This attribute is only relevant for ASCII work files. If a work file of another type than ASCII or ASCII-COMPRESSED is read, the specification of the attribute KEEPCR is ignored during runtime.

Warning:
Use KEEPCR with care. ASCII format is only recommended for alphanumeric data. Binary data should not be processed with ASCII work files. When you use KEEPCR, the work file record may include carriage return characters.

The use of KEEPCR only makes sense when reading ASCII work files which have been written on UNIX or OpenVMS. It does not make sense to use KEEPCR with ASCII work files which have been written on Windows.

REMOVECR Carriage return characters are removed when reading an ASCII work file. This is the default value.

This attribute is only relevant for ASCII work files. If a work file of another type than ASCII or ASCII-COMPRESSED is read, the specification of the attribute REMOVECR is ignored during runtime.

For further information on work files, see Work File Formats.