I'm a TSO bigot, but my main objections to Unix System Services (née MVS OpenEdition) have not been based ondislike for Unix. Rather, I saw two major flaws in the goals.
In the Unix world, there are requirements for certification, but there is a large ecology of tools that users have come to expect. My first impression of MVS-OE was that IBM was only interested in the tools required foor certification. That has gotten better over the years, but z/OS still doesn't come with all the tools that Unix users expect. IBM failed to seamlessly integrate Unix System Services with legacy services. Some exaples * Adding stream I/O to REXX only for Unix * The open() vs fopen() issue * Concatenating PDS(E) and directories -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [[email protected]] on behalf of René Jansen [[email protected]] Sent: Saturday, January 8, 2022 9:39 AM To: [email protected] Subject: Re: Ad programming features (Re: ... Re: Top 8 Reasons for using Python instead of REXX for z/OS I think USS is very interesting, a great technical accomplishment, but it is generally agreed that the differences with other Unices made life different for people wanting to use it in anger for applications. It gives z/OS the Unix system calls in a library that wraps MVS supervisor calls, and it offers an hierarchical filesystem in something that looks like a VSAM LDS to MVS. Differences with other Unices, like being EBCDIC based have been mostly masked, but will hit everybody sometimes, and did not make it less complicated. A lot of work was done on Rexx so it can address the conventional environments, and it even brought linein and lineout as standard components to MVS - a tender point un the Rexx world, because Endicott (it was?) closed the window on Rexx just before these became available for z/OS. These were available in a separate library that most often was not installed by sysprogs ‘because management’. Often seen wrongly by application people as a Unix ‘emulator’; USS is part of z/OS and makes it POSIX compliant. You can write a program that calls Unix services and MVS SVC’s (using their macros, preferably) in the same CSECT. Why you would do that is another question. It is truly a work of art, but all the younger people at sites where I needed to fight fires were pretty negative, and it always takes a lot of explaining. Also, wrong defaults on Java memory made it look terrible at first sight. Also, traditional sysprogs also refused to install bash and git and RACF-protected the C compiler, in a repeat of what happened when TCP hit the platform, making it even less popular, with no tab-expansion of filenames (tcsh cam first, and could do that, but also not very popular). This reminds me of OS/2’s “a better DOS than DOS”, which was absolutely true, but did not bring the marketing people what they expected. It would have been better to give away the C++ compiler (CSET/2) for free, astroturf the fora, and bribe the application developers and hardware people, like some other company did. BTW for a very short time I had the official job title ‘OS/2 Systems Programmer’ and it was a happy time solving lots of problems with the kernel debugger on the second machine. That stopped the Token Ring if it hit a breakpoint at the wrong moment. Best regards, René. > On 8 Jan 2022, at 09:58, PINION, RICHARD W. <[email protected]> wrote: > > I've not followed this thread. But, one thing I saw in your latest reply, > about z/OS USS/Open Edition and Linux. USS/Open Edition is/was a port of > UNIX. I remember the IBM marketing presentation about OE/USS, the local IBM > rep stated "more UNIX than UNIX". ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
