On 6/10/2010 4:16 PM, Kirk Wolf wrote:
I've got a program that writes full blocks using BSAM. Now I need to change it so that I can point to a BLOCK, *READ* it, and then re-WRITE it and continue writing sequentially from there.
OPEN for OUTPUT, specify MACRF=(RP,WP), write normally (and NOTE?). When needed, issue POINT, READ, POINT back to it, and WRITE. (I'm assuming you CHECK all I/O prior to POINT.) The WRITE will become the new last block in the data set.
I just don't want to trash the performance by adding support for "replacing a block" while writing.
I'm not clear what you wish to accomplish. If you only wish to replace a block without affecting subsequent ones, then this will not work. You either need to use BDAM or EXCP, or close the written data set and OPEN for UPDAT. All of these require DASD, and won't work for tape. Gerhard Postpischil Bradford, VT
