I apparently am having trouble speaking English - I thought I said
that in the open merge, "DCB" info coded into the DD/JFCB overrides
information from the DSCB. I did NOT say that is replaces the
information in the DSCB. IEBGENER and other utilities apparently use
RDJFCB (or open exits? or do an OBTAIN of the DSCB) and play games.
For a standard open (such as for a COBOL file) or a normal open in an
ASM program, attributes coded in the DD/JFCB override the information
from the DSCB. Consider a COBOL FD coded with "BLOCK CONTAINS nn"
where "nn" is not 0. If "nn" in this case is either not a multiple of
the LRECL, or is not greater than or equal to the DSCB BLKSIZE(for
input), you get an open error or I/O error. With a COBOL FD "BLOCK
contains 0", or a DCB BLKSIZE=0, then after the open, the program DCB
will contain the merged-in BLKSIZE attribute. As everyone is saying, I
think, any attributes coded in the DCB are not overridden by the
merged-in attributes. The merged information (with any attributes
coded in the program DCB having priority) are merged back to the JFCB,
and are merged back to the DSCB only if the open is for output.
Dale Miller
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
