NULLS—Control Null Spaces

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

Syntax


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

ON STD: Specifies that in fields containing any blank trailing space, the space is 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.

Description

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 the NULLS command, 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.

Note: When you swap screens in split screen mode, the nulls are replaced by spaces until you press an interrupt key, such as Enter, or a function key.

Examples

To set nulls mode on with all trailing blanks and all-blank fields written as nulls, enter this command:

NULLS ON ALL

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

NULLS ON STD

To set nulls mode off and thus have trailing blanks in each data field, enter this command:

NULLS OFF