NULLS—Set or Query Nulls Mode

The NULLS macro command sets nulls mode, which determines whether trailing blanks in each data field are written to the panel as blanks or nulls.

The NULLS assignment statement either sets nulls mode or retrieves the setting of nulls mode and places it in a variable.

Syntax


Macro command syntax

                   .-ON--STD-----.   
>>-ISREDIT--NULLS--+-------------+-----------------------------><
                   |     .-ALL-. |   
                   +-ON--+-----+-+   
                   +-STD---------+   
                   +-ALL---------+   
                   '-OFF---------'

ON STD: Specifies that in fields that contain any blank trailing space, the space is to be written as one blank followed by nulls. If the field is entirely empty, it is written as all blanks.
ON ALL: Specifies that all trailing blanks and all-blank fields are written as nulls.
OFF: Specifies that trailing blanks in each data field are written as blanks.


Assignment statement syntax

>>-ISREDIT--(var1,var2)-- = --NULLS----------------------------><


                        .-ON--STD-----.   
>>-ISREDIT--NULLS-- = --+-------------+------------------------><
                        |     .-ALL-. |   
                        +-ON--+-----+-+   
                        +-STD---------+   
                        +-ALL---------+   
                        '-OFF---------'

var1: The name of a variable to contain either ON or OFF.
var2: The name of a variable to contain ALL, STD, or blanks.
ON STD: Same as macro command syntax.
ON ALL: Same as macro command syntax.
OFF: Same as macro command syntax.

Description

The term data field normally refers to the 72 characters of data on each line. Using hardware tabs, however, you can split each line into multiple fields. See TABS—Define Tabs for more details.

Blank characters (X'40') and null characters (X'00') both appear as blanks. When you use the I (insert) line command, the data entry area appears as blanks for NULLS ON STD and as nulls for NULLS ON ALL.

Trailing nulls simplify use of the Ins (insert) key on the IBM® 3270 keyboard. You can use this key to insert characters on a line if the line contains trailing nulls.

Besides using NULLS, you can create nulls at the end of a line by using the Erase EOF or Del (delete) key. Null characters are never stored in the data; they are always converted to blanks.

Return codes

0: Normal completion
20: Severe error

Examples

To set nulls mode on with blank trailing space written as one blank followed by nulls and empty fields written as all blanks:

ISREDIT NULLS = ON STD

To set nulls mode off and thus have trailing blanks in each data field:

ISREDIT NULLS = OFF