On Mon, 7 Jan 2019 22:55:32 +0000, Savor, Thomas (Alpharetta) wrote: >I'm trying to write a copy program for Source code or Load Data from one Pds >to Another. >The Source Code part seems to be working...no issues. >The Load library code however, I cant seem to figure out how PDS2TTRT is >populated.
Copying a load module efficiently is much more complicated than you realize. Sure, you could just copy records from one PDS to the other, but that will not make efficient use of the space. When the Binder writes the TXT records to the PDS, it pays attention to how much space is left on the track, and, for each TXT record, it sets the record length roughly as follows: o If the amount of TXT to be written will fit on the track, and is less than the BLKSIZE, it uses that length, and is finished with TXT records for that load module. o The size of the TXT record will not exceed the BLKSIZE. o The size of the TXT record will not exceed the space available on the track. Remember that each member starts at some TTR location, where R is not necessarily zero. And the number of bytes available on the track where an output member starts is not necessarily, or even likely, the same as the number of bytes that were available on the track when the input member was written. It is my understanding that IEBCOPY does not do all of this, but instead calls the Binder to perform the copy. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
