weshinsley/keypress

Read individual keys in R without waiting for an ENTER

keypress

Read a single key press from the terminal

Installation

install.packages("keypress")

Usage

> has_keypress_support()
[1] TRUE

> x <- keypress()
> cat("You pressed key", x, "\n")
You pressed key h

Support

This is unfortunately impossible to do in

• RStudio,
• R.app (the builtin OSX GUI),
• RGui (the builtin Windows GUI),
• Emacs ESS, or
• if stdin() is not a terminal.

In other words, it pretty much only works interactively, in a terminal. The terminal can be pretty much any Linux, OSX, or other Unix terminal or Windows cmd (also called RTerm in R).

Keys

Note that not all keys are supported, in particular most of the modifiers (alt, shift, etc.) are not. Supported special keys are:

• Arrow keys: up, down, right, left. Available on most keyboards.
• Function keys: from f1 to f12. Available on most keyboards.
• Other special keys: enter, backspace, escape, tab.
• Some key combinations with the CONTROL key: ctrl-a, ctrl-b, ctrl-c, ctrl-d, ctrl-e, ctrl-f, ctrl-h, ctrl-k, ctrl-l, ctrl-n, ctrl-p, ctrl-t, ctrl-u, ctrl-w.
• Keys typically not availale on OS X keyboards: home, end, insert, delete, pageup, pagedown.
• On Linux and OS X Unicode characters are supported, but not (yet) on Windows. Unicode characters are returned UTF-8 encoded.

License

MIT © Gábor Csárdi