[Rcpp-devel] R_Interactive vs R_NoEcho

[Simon Urbanek]

> On Feb 2, 2023, at 11:41 AM, Dirk Eddelbuettel <edd at debian.org> wrote:
> 
> 
> On 1 February 2023 at 17:23, Dominick Samperi wrote:
> | Since I am not aware of an R-internals mailing list, and since this
> 
> AFAIK there is no such mailing list. There is a manual of that name:
> https://rstudio.github.io/r-manuals/r-ints/  (nicer quarto rendered version)
> 
> Or did you mean the r-devel list?
> 
> | question is related to the behavior of RInside::repl(), perhaps this is the
> | appropriate place to post this question.
> | 
> | The function Rstd_ReadConsole() in src/unix/sys-std.c results in the
> | user command being echoed when R_Interactive = false,
> | and R_NoEcho = false.
> | 
> | But if we set R_NoEcho = true to stop the echo, the prompt is also
> | suppressed. Setting R_Interactive = true (with R_NoEcho = false)
> | does not suppress the prompt, but it has other side-effects like
> | enabling the final confirmation question. Again, if we set R_NoEcho = true
> | there is no prompt.
> | 
> | So my question is: why does setting R_NoEcho=true turn off the prompt?
> 
> Sounds like an r-devel question to me.  Nothing Rcpp related here.  Simon and
> Tomas both hang out here so if you are lucky they may see it.  Else I'd try
> over there.
> 

We do ;). Well, the prompt is part of the echo - in R you can't have a prompt when you are not echoing the command since you'd just see > > > which is not very helpful. But I know nothing about RInside so can't comment on what you are trying to do.

Cheers,
Simon