Z Open Automation Utilities has a dtouch command that is equivalent to Unix touch
On Fri, Aug 2, 2024, 4:08 PM Michael Oujesky <[email protected]> wrote: > "last reference" is the date of the last successful open of the file, > regardless of whether for input or output. Allocation without > opening the file does not change the last reference date. > > Michael > > At 03:30 PM 8/2/2024, Phil Smith III wrote: > > >Billy Ashton asked how to do the equivalent of a USS "touch" on a > >z/OS data set. > > > >I'm wondering if there's something like the C "DD:ddname" filename > >specification hack that could be used. I know this would seem odd: > >run a batch job that uses BPXwhatever to run USS "touch", but if > >it's possible...? > > > >This makes me realize that I don't know what "touch" actually does. > >I mean, I know the effect, but what does it have to do to make that > >happen? If it's some filesystem function, a minimal C program might > >be able to use the "DD:ddname" hack and that function. Googling > >suggests that it just opens the file and that that's sufficient to > >update it, but there has to be more, since it can optionally update > >just the last access time, without updating the last changed time. > > > >In fact, the more I think about this, I now wonder what "last > >referenced" even means; I assume it's time of last access, not change? > > > >Billy wrote, in part: > > > We don't want to do things like allocate, open, and print one record, > > > as some of these files are huge (25-50GB). > > > >Would you need to print a record to update "last referenced"? > >Shouldn't reading a record suffice? Do you even need to do that? Why > >does the size of the file matter here? > > > >I'm sure these are dumb questions but my in-depth filesystem > >knowledge is for other OSes, so I'm just knowledgeable enough to be > curious... > > > >---------------------------------------------------------------------- > >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 > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
