[R-pkg-devel] How to fix: non-standard things in the check directory: 'NUL' ?

[Ivan Krylov]

Dear Friedemann von Lampe,

Welcome to R-package-devel! This is a good, concise description of the
problem, but please also provide a link to your code in the future.

В Wed, 13 Dec 2023 09:58:41 +0100
Friedemann von Lampe <friedemann.vonlampe using biologie.uni-goettingen.de>
пишет:

> Flavor: r-devel-linux-x86_64-debian-gcc
> Check: for non-standard things in the check directory, Result: NOTE
> Found the following files/directories:
> 'NUL'

The file named 'NUL' is created in the function screeplot_NMDS:

R/screeplot_NMDS.R:  capture.output(nmds_i <- invisible(metaMDS(matrix,
distance = distance, k = i, trymax = trymax, engine = "monoMDS",
autotransform = autotransform)), file='NUL')

https://github.com/fvlampe/goeveg/blob/db94c4a567eeac67b6df1df5a4f2d1aa771e629a/R/screeplot_NMDS.R#L76

On Windows, everything goes right and the output is redirected to the
null device. On Linux, the null device is '/dev/null', not 'NUL', and
this name doesn't hold any special powers, so the file with this name
gets created.

Use the base function nullfile() to obtain the name of the null device
in a portable manner. I think you can also not supply the `file`
argument and ignore the return value of the capture.output(...)
expression. This may be less efficient if there's truly a lot of output.

-- 
Best regards,
Ivan