David, All, I have to think about hardening a COBOL written STC performing security calls. This my main reason for the question regarding the I/O error handler, it makes sense to move the I/O into an assembler module or C..
Scott On Fri, Aug 25, 2017 at 12:07 AM David Crayford <dcrayf...@gmail.com> wrote: > On 25/08/2017 11:10 AM, Farley, Peter x23353 wrote: > > That may well be true, but use of C stdio then requires POSIX mode, > which makes it not suitable for a *generalized* file handler which might, > for instance, need to be invoked in a totally non-LE environment. > > Good point about the non-LE environment. The only time I run non-LE > these days is systems level programming and I don't do much of that. I'm > doing a lot of Java work these days and C stdio pops it's head up again > when using ZFile. It's remarkable that I only need one simple wrapper > class to access all the different file types on z/OS. It's not perfect > though. I wish it had better support for enumerating PDS members. > > There is no POSIX requirement for C stdio (or sockets). In my experience > the only time I've required POSIX semantics is to use runtime functions > for threads, mutexes and IPC stuff. > > > I would agree with "hundreds of lines" but not thousands. QSAM support > only takes a few hundred, even including MOVE/LOCATE and UPDATE modes (and > a lot of that can be explanatory comments for the next maintainer). Maybe > by the time the BSAM/BDAM/VSAM support was done you would have a thousand > or more lines, but not I think two or three thousand. > > > > Depending on how many bells and whistles you want to include of course. > As usual, YMMV. > > We've got a common code assembler VSAM I/O program that's ~1700 LOC, but > it does have quite a few bells and whistles. fopen() has extra bling > like dynamic allocation. Our assembler dynalloc routine is 987 LOC. It > all adds up and that's before adding extra layers of abstraction. > > > > > Peter > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > On Behalf Of David Crayford > > Sent: Wednesday, August 23, 2017 12:53 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: Cobol Help > > > > On 22/08/2017 11:59 PM, Farley, Peter x23353 wrote: > >> In that case the assembler I/O modules handled any errors that they > could (SYNAD, etc.) and passed back error code(s) and messages to the COBOL > interface module to pass up to the caller, simulating COBOL FILE STATUS and > VSAM error variable where possible. > >> > >> Metal C might be a better choice for more generalized file I/O > handling, one small step above assembler but with all assembler facilities > available. > > The best generalized file handling I've seen on z/OS is the C stdio > > fopen() and friends (by a country mile). That one factory function can > handle all the standard access methods: BSAM, QSAM, VSAM (KSDS, RRDS, > ESDS), hiperspaces and Unix files. It's a thing of beauty. To code the > equivalent functionality in Metal/C would take hundreds if not thousands of > lines of code. > > > > -- > > > > > > This message and any attachments are intended only for the use of the > addressee and may contain information that is privileged and confidential. > If the reader of the message is not the intended recipient or an authorized > representative of the intended recipient, you are hereby notified that any > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please notify us immediately by > e-mail and delete the message and any attachments from your system. > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- Scott Ford IDMWORKS z/OS Development ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
