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Is there a way to prevent a command from printing any output?

I was using the nnet function from the package with the same name and it printed some information that I didn't need, making noise in the output of my own program. I found out that with the parameter trace=FALSE the function would run quietly, but now I'm wondering what would happen if a function didn't accept such an argument.

In other words, would it be possible to temporarily disable the output in R?

Edit

To be more specific, I mean the standard output, the one you have with print. For example, something like this:

print("a")
disable_output()
print("b")
enable_output()
print("c")

with the following output:

[1] "a"
[1] "c"
Miguel
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  • `? suppressMessages` `?suppressPackageStartupMessages` `?suppressWarnings` – G5W Sep 07 '20 at 18:15
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    I deleted my answer. Why? Based on the updated explanation your question is answered by https://stackoverflow.com/questions/2723034/suppress-output-of-a-function see Danny's answers using sink() – Technophobe01 Sep 07 '20 at 18:31
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    @Technophobe01 Thanks! – Miguel Sep 07 '20 at 20:44
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    +1 to @Technophobe01 for the suggestion! Anyway pay particular attention to use sink() out of functions and/or without protect yourself from against whatever could happen while the sink is open. – Corrado Sep 10 '20 at 18:03

1 Answers1

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I think you can divert output globally only to a file (I do not know if you can completely disable it). You can look at ?sink as a starting point.

On the other hand, you can use:

?capture.output: Evaluates its arguments with the output being returned as a character string or sent to a file.

and

?invisible: Return a (temporarily) invisible copy of an object.

To write a function which evaluates its arguments without throwing any (standard) output (note, it could be useful to include ?force in the function's body to force the evaluation of its argument):

invisible(capture.output(print("foo")))

without_output <- function(x) {
    invisible(capture.output(force(x)))
}

without_output(print("foo"))

Created on 2020-09-07 by the reprex package (v0.3.0)

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Corrado
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