[Rd] certain pipe() use cases not working in r-devel

[Jennifer Bryan]

I've now tested with:

> R.version.string
[1] "R Under development (unstable) (2024-02-16 r85931)"

and all of the previously mentioned examples now work as expected on macOS.

Thanks for the quick fix,
Jenny

On Thu, Feb 15, 2024 at 8:02 AM Tomas Kalibera <tomas.kalibera using gmail.com>
wrote:

>
> On 2/14/24 23:43, Jennifer Bryan wrote:
> > Hello,
> >
> > I've noticed a specific type of pipe() usage that works in released R,
> but
> > not in r-devel.
> >
> > In 4.3.2 on macOS, I can write to a connection returned by pipe(), i.e.
> > "hello, world" prints here:
> >
> >> R.version.string
> > [1] "R version 4.3.2 (2023-10-31)"
> >> con <- pipe("cat")
> >> writeLines("hello, world", con)
> > hello, world
> >
> > But in r-devel on macOS, this is silent no-op, i.e. "hello, world" does
> not
> > print:
> >
> >> R.version.string
> > [1] "R Under development (unstable) (2024-02-13 r85895)"
> >> con <- pipe("cat")
> >> writeLines("hello, world", con)
> > My colleague Lionel Henry confirms he sees the same results on linux.
> > This particular example with cat doesn't work on Windows, so I don't have
> > any useful observations for that OS.
> >
> > You might say this is a weird example or use case. The actual usage
> where I
> > discovered this is the way folks read/write the clipboard on macOS using
> > pbcopy/pbpaste (and, in very similar ways, on linux using xsel or xclip).
> > This is mentioned in the "Clipboard" section of the connections help
> topic.
> >
> > In 4.3.2 on macOS, I can successfully roundtrip with the clipboard:
> >
> >> pb_write <- pipe("pbcopy")
> >> writeChar("hello clipboard!", pb_write, eos = NULL)
> >> pb_read <- pipe("pbpaste")
> >> readChar(pb_read, 16)
> > [1] "hello clipboard!"
> >
> > In r-devel, it appears that the write operation silently does nothing:
> >
> >> pb_write <- pipe("pbcopy")
> >> writeChar("hello clipboard!", pb_write, eos = NULL)
> >> pb_read <- pipe("pbpaste")
> >> readChar(pb_read, 16)
> > character(0)
> >
> > If the clipboard is populated through other means, I can
> > use readChar(pipe("pbpaste"), ...) to read the clipboard even in r-devel.
> > So this seems to be specific to writing to the connection.
> >
> > Is this change in behaviour intentional and will it be present in the
> next
> > release of R? FWIW, I did a crude search of the source of all CRAN
> packages
> > and there are quite a few currently using pipe() for clipboard access on
> > *nix.
>
> This should be fixed now in R-devel. Thanks for the report and thanks to
> Ivan for the debugging. It would be great if you could test on your end
> with different examples and report any other issues.
>
> Thanks
> Tomas
>
> >
> > -- Jenny
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-devel using r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
>

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