Dynamically load user32.dll from R & call external function

Question

I try to access user32.dll functions in R Session. I used the code:

dyn.load("c://windows//system32//user32.dll")
.External("MessageBeep", 0L)

But R session crashes. According to documentation .External is intended to use during R package creation. However there was no prohibition to use it as shown above.

I am using Windows 8 and RStudio (1.1.453) / R (3.5.0). Could you advise a proper way to call external Windows functions from R session?

Answer 1

You are accessing the Win32 C API, thus you can load the user32.dll, and then use the Foreign {base} .C() call too access the Window32 MessageBeep function.

##Example Code

dyn.load("c://windows//system32//user32.dll")
.C("MessageBeep")

##Runtime Output

> dyn.load("c://windows//system32//user32.dll")
> .C("MessageBeep")
list()
> 

You should hear the Windows Message "Beep" - Alas, I have yet to figure out how to include sounds in solutions (chuckle).

Note: I'd also recommend you take a look at the Rcpp package, I am a big fan.