what is the meaning of 'sysin dd dummy'

Answer Posted / deepak gairola

//sysin dd dumy :DUMMY has meaning as NULLFILE and is used
to suppress unused files. If you use it, it handles files
as non existing.
You can use it for example in IDCAMS with various input and
output files.
You have 20 input and 20 output files, but you only want to
use the 9th thru 13th input/output files without changing
the sysin instructions (REPRO).
So you set input/output file 1 thru 8 and 14 thru 20 to DD
DUMMY.
It works, try it.

Please go through the manual before posting

If you use it in a concatenated DD statement, be careful,
because it
identifies the EOF in the DD DUMMY, so it is the best way
to place it
at the end of a DD instruction.

All parameters used after a DD DUMMY, are ignored, this is
the difference between NULLFILE and DD DUMMY. NULLFILE
recognizes applied parameters.

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