[R] file.access returning -1 for a file on remote Windows drive.

[Sam Albers]

Thanks Jeff. And for future readers head here:

https://github.com/eddelbuettel/digest/issues/49

and here:

https://github.com/eddelbuettel/digest/issues/13


Sam

On Fri, Feb 28, 2020 at 3:40 PM Jeff Newmiller <jdnewmil using dcn.davis.ca.us> wrote:
>
> Read the closed issues in his digest Github repo first... this discussion has already occurred there.
>
> On February 28, 2020 3:35:09 PM PST, Sam Albers <tonightsthenight using gmail.com> wrote:
> >Great question Will. If it were my code I would definitely do this.
> >However the problem is manifesting itself for my work with Dirk's
> >great digest package here:
> >
> >https://github.com/eddelbuettel/digest/blob/947b77e82b97024a874a808a4644be21fc329275/R/digest.R#L170-L173
> >
> >So because file.access is saying the permissions aren't right, I get
> >an error message from digest and can't create a hash. Knowing full
> >well that this is some weird Windows thing but also knowing I am stuck
> >in that environment, I wanted to figure where I was seeing a
> >difference between those two functions before I went asked Dirk if
> >he'd be interested in a change to that particular bit of code.
> >
> >
> >On Fri, Feb 28, 2020 at 3:28 PM William Dunlap <wdunlap using tibco.com>
> >wrote:
> >>
> >> If file.access() says the file is unreadable but file() says it can
> >be opened, why don't you
> >> just open the file and read it?  You can use tryCatch to deal with
> >problems opening or
> >> reading the file.
> >>
> >> Bill Dunlap
> >> TIBCO Software
> >> wdunlap tibco.com
> >>
> >>
> >> On Fri, Feb 28, 2020 at 2:54 PM Sam Albers
> ><tonightsthenight using gmail.com> wrote:
> >>>
> >>> Thanks Jeff. I am probably not explaining myself very well but my
> >>> question under what circumstances would
> >>>
> >>> summary(file(remote_file, "rb"))$`can read`
> >>>
> >>> be different from:
> >>>
> >>> file.access(remote_file, 4)
> >>>
> >>> If my permissions were different across remote and local should that
> >>> not be reflected in both of these functions?
> >>>
> >>> On Fri, Feb 28, 2020 at 2:37 PM Jeff Newmiller
> ><jdnewmil using dcn.davis.ca.us> wrote:
> >>> >
> >>> > Dunno. They agree for me. Maybe look closer at all permissions via
> >Windows File Manager?
> >>> >
> >>> > On February 28, 2020 2:06:34 PM PST, Sam Albers
> ><tonightsthenight using gmail.com> wrote:
> >>> > >Some additional follow-up:
> >>> > >
> >>> > >> summary(file(remote_file, "rb"))$`can read`
> >>> > >[1] "yes"
> >>> > >
> >>> > >> summary(file(local_file, "rb"))$`can read`
> >>> > >[1] "yes"
> >>> > >
> >>> > >compared to:
> >>> > >
> >>> > >> file.access(local_file, 4)
> >>> > >local.R
> >>> > >         0
> >>> > >
> >>> > >> file.access(remote_file, 4)
> >>> > >remote.R
> >>> > >            -1
> >>> > >
> >>> > >Can anyone think why file.access and file would be contradicting
> >each
> >>> > >other?
> >>> > >
> >>> > >Sam
> >>> > >
> >>> > >On Fri, Feb 28, 2020 at 10:47 AM Sam Albers
> >>> > ><tonightsthenight using gmail.com> wrote:
> >>> > >>
> >>> > >> Hi there,
> >>> > >>
> >>> > >> Looking for some help in diagnosing or developing a work around
> >to a
> >>> > >> problem I am having on a Windows machine. I am running R 3.6.2.
> >>> > >>
> >>> > >> I have two identical files, one stored locally and the other
> >stored
> >>> > >on
> >>> > >> a network drive.
> >>> > >>
> >>> > >> For access:
> >>> > >>
> >>> > >> > file.access(local_file, 4)
> >>> > >> local.R
> >>> > >>          0
> >>> > >>
> >>> > >> > file.access(remote_file, 4)
> >>> > >> remote.R
> >>> > >>             -1
> >>> > >>
> >>> > >> Also for file.info
> >>> > >>
> >>> > >> > file.info(local_file)$mode:
> >>> > >> [1] "666"
> >>> > >>
> >>> > >> > file.info(remote_file)$mode:
> >>> > >> [1] "666"
> >>> > >>
> >>> > >> Ok so I am access issues. Maybe they are ephemeral and I can
> >change
> >>> > >> the permissions:
> >>> > >>
> >>> > >> > Sys.chmod('remote.R', mode = '666')
> >>> > >> > file.access(remote_file, 4)
> >>> > >> remote.R
> >>> > >>             -1
> >>> > >>
> >>> > >> Nope. I am thoroughly stumped and maybe can't make it any
> >further
> >>> > >> because of Windows.
> >>> > >>
> >>> > >> Downstream I am trying to use digest::digest to create a hash
> >but
> >>> > >> digest thinks we don't have permission because file.access is
> >>> > >failing.
> >>> > >> Any thoughts on how I can get file.access to return 0 for the
> >>> > >remote.R
> >>> > >> file? Any ideas?
> >>> > >>
> >>> > >> Thanks in advance,
> >>> > >>
> >>> > >> Sam
> >>> > >
> >>> > >______________________________________________
> >>> > >R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>> > >https://stat.ethz.ch/mailman/listinfo/r-help
> >>> > >PLEASE do read the posting guide
> >>> > >http://www.R-project.org/posting-guide.html
> >>> > >and provide commented, minimal, self-contained, reproducible
> >code.
> >>> >
> >>> > --
> >>> > Sent from my phone. Please excuse my brevity.
> >>>
> >>> ______________________________________________
> >>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>> https://stat.ethz.ch/mailman/listinfo/r-help
> >>> PLEASE do read the posting guide
> >http://www.R-project.org/posting-guide.html
> >>> and provide commented, minimal, self-contained, reproducible code.
>
> --
> Sent from my phone. Please excuse my brevity.