Converting FB file to VB file and vice versa using SORT

Converting Fixed Block file to Variable Block file

We can use FTOV to do this conversion

SORT Parameters:

SORT FIELDS=COPY

OUTFIL FNAMES=VBOUT,FTOV

VBOUT is the output file of variable length

If the input file is 80 bytes FB file, then VB file will be created with 84 bytes where 4 bytes if for RDW

VBOUT length should be extra 4 bytes for RDW(Record Descriptor Word)

The total length of the record in VB file is RDW (4 bytes) + actual record length

Converting Variable Block file to Fixed Block file

We can do it using VTOF in SORT

SORT parameters:

SORT FIELDS=COPY

OUTFIL FNAMES=FBOUT,VTOF,OUTREC=(5,76)

If VB file is 80 bytes, the FB file will be created with 76 bytes.

OUTREC is mentioned as the data is to be copied from 5th position where first 4 bytes is for RDW and doesn’t contain any data.

When the system stores VB file, it puts 4 bytes RDW (Record Descriptor Word) in front of each record where first 2 bytes is a binary half word of length S9(04) COMP which contains length of the record including RDW itself and other 2 bytes contain zeros.