On Aug 29, 2018, at 8:20 PM, Andrew Rowley <[email protected]> wrote: > > On 30/08/2018 12:16 AM, Jerry Callen wrote: >> The whole idea of holding a lock on a file while a human being slowly edits >> it is so 1960s. >> >> Since at least the mid 1970s, editors like emacs have loaded the file for >> editing and noted the timestamp. >> When the user attempts to save the file. the timestamp is checked again, and >> if it changed, the user is asked what to do.
> I always thought this was a result of being unable to effectively prevent > simultaneous edits, not a feature. Of course it's possible to prevent simultaneous edits, at least to the extent that you claim ISPF does. ISPF doesn't REALLY prevent simultaneous edits; it relies on a convention, and you have to hope that everyone follows the convention. That's the issue that started this thread. In Unix that's traditionally been done with a lock directory playing the role of an ENQ, but it can be done. It's just that -- no one does, because source control is a better solution. > The user is asked what to do - do you want to throw away your changes or the > other guy's changes? > The answer is always the other guy's changes, right? No. It's trivial to save my copy of the file with another name, load the other guy's changes, and merge them. Of course, that's because I use emacs. Your mileage (with less capable editors) may vary. [Discussion of merging and its perils elided] Here's the dirty little secret: simultaneous edits of the exact same file (in non-z/OS contexts) are uncommon. I'll go out on a limb and bet that even in z/OS, simultaneous edits of even the exact same file are uncommon. If you're not using source control system, then, yes, preventing those rare occurrences is a big deal. What IS common is simultaneous edits to COPIES of the same file (in user sandboxes), and that's why merge tools exist. But - why not use a source control system and prohibit direct editing-in-place of critical things libraries like PARMLIBs, PROCLIBs, etc? You already have many system libraries under SMP control; no direct changes to, say, SYS1.LINKLIB. You COULD put everything else under SMP, but the effort to do so is just too high. This is where modern source control systems come in - control, with minimal pain. I keep hammering on this because I think it really MATTERS. If you're a systems programmer, you ought to be at the head of line when it comes to adopting tools that allow you to bring consistency and order to system maintenance. It's early days for Zowe. The crucial first step was to get a framework in place into which. Zowe builds on the back-end framework of ZOSMF and similar services and provides a modern, responsive web UI for those services. What comes next is, to some extent, up to all of us. Remember when OS/360 was open source, and brought us things like HASP? Zowe is a return to those roots. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
