On Tue, 16 Sep 2025 11:24:38 -0500, Charles Mills wrote: >Follow-up question if I may: > >Would you expect (your command(s) here) | cp - "//DD:MYDDNAME" to work if the >command were executed from Rexx using SYSCALLS and BPXWUNIX? > or ADDRESS SYSCALL spawn.
>(Assuming all of the usual -- good allocation, RACF authorization, no ENQ >conflicts, etc.) > Some programmers rely on _BPX_SHAREAS=MUST for this. I believe redirection needs a descriptor. open() returns a descriptor but doesn't handle Classic data sets. fopen() handle s Classic data sets but doesn't return a descriptor. After fopen(), fileno() returns the file descriptor for the FILE. <https://www.ibm.com/docs/en/zos/3.1.0?topic=functions-fileno-get-file-descriptor-from-open-stream> MVS data sets are not supported, so fileno() of an MVS data set returns -1. Some operations on UNIX files are nearly impossible on MVS data sets. >I am asking because the doc says > >In order to use the //DD:DDNAME format, the dataset must be allocated in the >address space that the following command will run in. However, in the login >shell environment, the user cannot use the //DD:DDNAME format due to the >restriction that the address space of the allocated dataset is not always the >same as the running command. > >I read that as "it might work, and it might not -- and even if it worked in >test, it might not work in production." -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
