INFDS Input/Output Feedback Example
To specify an INFDS which contains fields in the input⁄output feedback
section, you can make the following entries:
- Specify the INFDS keyword on the file description specification with the name of the file information data structure
- Specify the file information data structure and the subfields you wish to use on a definition specification.
- Use information in the Information Center to determine which
fields you wish to include in the INFDS. To calculate the starting position
and length of the
subfields of the input/output feedback section of the INFDS,
use the Offset, Data Type, and Length given in the Information Center and
do the following calculations:
Start = 241 + Offset
Character_Length = Length (in bytes)
For example, for device class of a file, the Information Center gives:
Offset = 30
Data Type is character
Length = 2
Therefore,
Start = 241 + 30 = 271
See subfield DEV_CLASS in the example below