Changing the processing attributes

• chained/non-chained input/output

• number of blocks to be transferred.

If one of these values is to be changed during processing of the file, the following actions are required:

1. Close file

2. Modify fields in MFCB

3. Reopen file

The value for the number of blocks to be transferred should be changed if, for example, fewer blocks are to be transferred in the last write operation than was specified when the file was opened.

Example

99 blocks are to be written to an EAM file. Chaining is to be used, with 15 blocks being transferred per write call (byte IDMFNHP in the MFCB). The following operations are then requested:

OPEN (new file) -> WRITE -> WRITE -> WRITE -> WRITE -> 
WRITE -> WRITE -> CLOSE *) -> REOPEN -> WRITE -> 
REOPEN -> WRITE -> CLOSE




*)	After 6 write operations, there are still 9 blocks to be written. The file must therefore be closed and then reopened, this time with a value of 9 set for the number of blocks to be transferred.