Processing of empty blocks (EMPTY-BLOCK operand)
The EMPTY-BLOCK operand in the ASSIGN-INPUT-FILE statement enables the user to control whether an empty block is skipped or whether an empty block (before the HIGHEST-USED-PAGE (LAST-PAGE-POINTER) in a file) is to be processed as an input record with the contents binary zero (X’00’).
Block structure (BLOCK-CONTROL-INFO operand)
BLOCK-CONTROL-INFO=*PAMKEY
Each logical block forms an input record with the length specified by BUFFER-LENGTH. For the gap test, the coded file identification (CFID) given in the PAM key of the first PAM block of the logical block is compared with the one entered in the catalog.
If they are not identical, the logical block is processed in accordance with the value for EMPTY-BLOCK.If ACCESS-METHOD=*PAM and BLOCK-CONTROL-INFO=*PAMKEY have been specified for the output file, the user data areas in the PAM keys are passed to the output file, but they do not form part of the record.
Note
If BLOCK-CONTROL-INFO=*PAMKEY has been specified for the PAM input file and no output file has the specification BLOCK-CONTROL-INFO=*WITHIN-DATA or *NO, each PAM block forms an input record with a length of 2048 bytes.The coded file identification given in the PAM key of each PAM block is used for the gap test. If a comparison yields discrepancies, the PAM block is processed in accordance with the EMPTY-BLOCK value specified in the ASSIGN-INPUT-FILE statement.
BLOCK-CONTROL-INFO=*WITHIN-DATA
Each logical block forms an input record with the length BUFFER-LENGTH minus 12. The block control field is not part of the input record. For the gap test, the CFID in the block control field of the logical block is used.
If a comparison yields discrepancies, the logical block is processed in accordance with the value specified for the EMPTY-BLOCK operand.BLOCK-CONTROL-INFO=*NO
Each logical block forms an input record with the length specified by BUFFER-LENGTH. Since no gap test can be performed, all logical blocks are processed.Blocks at the end of this file which do not belong to it (block number greater than HIGHEST-USED-PAGE (LAST-PAGE-POINTER)) are not transferred.