How to capture the output of system()

Question

This question was motivated by Rmarkdown not outputting results of system command to html file. For some reason, the output of system() in R (or system2()

Answer 1

You could add a function knitr::system that masks base::system. Users could work with it like it was system::base, but the output can be captured by capture.output:

system <- function(...) {
  stopifnot(!any(names(list(...)) %in% "intern"))
  result <- base::system(..., intern = TRUE)
  print(result)
}

I admit, that this is somewhat hacky, and to be honest, I'm not sure about possible side effects. But I think it could be worth a try.