Reading user input without echoing

Question

I'm wondering if there is a way that I can read user input from STDIN without echoing it back to the screen in R. I know that readline(), readLines() and scan() can read in user input from the keyboard but none appear to have an option to not echo back.

As you might expect this is to grab a password. So I'm looking for something that would let me do:

> a<-get_password()
Password:
> a
[1] "password"

Can't be done cross-platformly easily, usual solution is tcltk: http://stackoverflow.com/questions/2917202 - but if you really need it from STDIN... — Spacedman, Mar 01 '11 at 13:04
possible duplicate of [R: Way to securely give a password to R application?](http://stackoverflow.com/questions/2917202/r-way-to-securely-give-a-password-to-r-application) — Joris Meys, Mar 01 '11 at 13:22

Noah · Accepted Answer · 2011-03-01T12:54:18.617

10

What's the operating system? If you can run it from a terminal, this should work.

get_password <- function() {
cat("Password: ")
system("stty -echo")
a <- readline()
system("stty echo")
cat("\n")
return(a)
}

> a <- get_password()
Password: 
> a
[1] "sdfs"
>

This works on OS X using R from Terminal.app, but not from R.app. No idea on a Windows solution, since there doesn't seem to be a native R solution.

edited Mar 01 '11 at 12:54

answered Mar 01 '11 at 12:43

Noah

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12

This is great, at the moment I'm only dealing with Mac/Linux so this will serve perfectly. Thanks! – David Lawrence Miller Mar 01 '11 at 13:24
1

This works on Linux (tested on Ubuntu) as well, as expected given that it's a UNIX-based trick. – Ari B. Friedman Mar 01 '11 at 13:36

score 5 · Answer 2 · answered Mar 01 '11 at 13:38

5

If this is for a more production-style environment, then you might consider using R-Tcl/Tk, which has a "Show" parameter for password entry.

answered Mar 01 '11 at 13:38

Ari B. Friedman

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Reading user input without echoing

2 Answers2

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