On 2018-09-06 1:41 PM, Brian Westerman wrote:
Apparently some of the libraries shipped by some vendors or at least the directions to define them specify RECFM=U,LRECL=256.
Maybe the vendor instruction writers looked at their data sets and copied the attributes they saw.
So, I had this TSO command called REVIEW which read PDS directories using RECFM=F,LRECL=256,BLKSIZE=256 with QSAM. Years later I noticed that it seemed to be setting the LRECL of RECFM=U data sets to 256, although I maintain that it did not do that when first developed.
So, with DCB attribute merging, the VTOC entry got zero fields updated from the JFCB even though it was only opened for INPUT. Or maybe I added a feature which could update the PDS, and it was on these occasions which added a non-zero LRECL to the VTOC entry. The result was that my RECFM=U data sets processed by this program ended up with LRECL=256.
Whatever the actual details were that caused this update, the LRECL-changing phenomenon all went away when I removed the LRECL value from the directory-reading DCB. Looking at the source now, it says RECFM=F and BLKSIZE=256, but the "problem" as not occurred with this combo.
Once the LRECL is set, it won't go away unless removed by "unnatural" means. So maybe someone used this or a similar program on their library at some stage.
Cheers, Greg ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
