IBM's ftp has a "locsite rdw" which adds an RDW (record descriptor word) to each record in a RECFM=V file. You can see an example here:
https://sourceforge.net/p/pdos/gitcode/ci/master/tree/pdpclib/folks.c Apparently VM supports that (in ftp) too. I recently found out that IBM basically has another "standard" form for length indicators, which is a 2-byte form. So while a record length of 80 bytes of data is represented by 4 bytes in an RDW, plus it includes the length of the RDW itself, so you would get x'0054 0000' for that RDW, the 2-byte form is x'0050'. You can see that here: https://www.vm.ibm.com/download/vmarc.html Click here and instruct your browser to save the file to disk, [~/Downloads] hexdump vmarc.module 0 200 000000 00500002 03800002 00000002 34980002 .P..........4... 000010 349880F1 1F3A0000 00000000 000000DB 4....:.......... 000020 B3E04C00 00800000 0000000A 00035000 ..L...........P. 000030 00000000 00000000 0000FFEF 0000E900 ................ 000040 00000000 00000000 00000000 00000000 ................ 000050 00003498 C39697A8 99898788 A3404D83 ..4..........@M. 000060 5D40F1F9 F8F960F1 F9F9F46B 40D19688 ]@....`....k@... You can see that 2-byte value of x'0050' at offset 0, then x'0050' worth of data, so the next 2-byte (halfword) is seen at offset x'52'. Because the length of the RDW is not included in the halfword length, it means you can have a maximum of x'FFFF' data per record, and in fact, CMS does exactly that with its executables (MODULE format), maxing the record out to the full 65535 bytes of data per record - way above the 32760 minus 8 that MVS can support. Given that this "standard" exists, is there a formal name for it? I was thinking RDH - record descriptor halfword, as an alternative to the more normal RDW - record descriptor word, but I now realize that this may be confusing, because of the different nature (length of record descriptor itself not included). It's odd that IBM doesn't have an ftp option (that I am aware of) to produce an RDH or whatever format file from RECFM=V instead of RDW, for transporting CMS files. I could submit a RFE to add that, but IBM still hasn't (that I am aware of) implemented my existing RFE to allow the ftp of RDW files to go both ways, so that I can send a RECFM=V binary file with embedded RDWs TO MVS. In the meantime, I have my own tools to do this, and I would now like to write more tools. I could have an RDW to RDH conversion tool as well, for example. RDH to RDW would also work, up to a point. (And I could produce an error or warning if the soft or hard limits are exceeded, or maybe even create a theoretical spanned record in the RDW - even if it exceeds the limits of what IBM utilities can handle, I could still store it in a RECFM=U file for later use by CMS - but I'm not sure there is a reason to do that). What I'd like to know is - is there a formal name already for the RDH length format? If not, is RDH reasonable, or is there a better suggestion? It may be considered too simple/obvious that it was just called a "length indicator" rather than being formally named. I'd like a semi-formal name, so that I can call my utility RDW2RDH.C instead of rdw_to_length_indictator.c Thanks. Paul. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
