keypress.md
In cli: Helpers for Developing Command Line Interfaces

control characaters

Code
  for (code in c(1:2, 4:6, 8:14, 16L, 20L, 21L, 23L, 27L, 127L)) {
    p$write_input("cli::keypress()\n")
    Sys.sleep(0.1)
    p$write_input(as.raw(code))
    p$poll_io(1000)
    cat(p$read_output())
  }
Output
  [1] "ctrl-a"
  [1] "ctrl-b"
  [1] "ctrl-d"
  [1] "ctrl-e"
  [1] "ctrl-f"
  [1] "ctrl-h"
  [1] "tab"
  [1] "enter"
  [1] "ctrl-k"
  [1] "ctrl-l"
  [1] "enter"
  [1] "ctrl-n"
  [1] "ctrl-p"
  [1] "ctrl-t"
  [1] "ctrl-u"
  [1] "ctrl-w"
  [1] "escape"
  [1] "backspace"

write ahead

Code
  p$write_input("{ Sys.sleep(0.5); cli::keypress() }\nX")
  p$poll_io(1000)
Output
    output    error  process 
   "ready" "nopipe" "silent" 
Code
  cat(p$read_output())
Output
  [1] "X"

arrows, etc

Code
  for (key in keys) {
    p$write_input("cli::keypress()\n")
    p$write_input(key)
    p$poll_io(1000)
    cat(p$read_output())
  }
Output
  [1] "up"
  [1] "right"
  [1] "left"
  [1] "end"
  [1] "home"
  [1] "-"
  [1] "up"
  [1] "down"
  [1] "right"
  [1] "left"
  [1] "end"
  [1] "home"
  [1] "-"
  [1] "home"
  [1] "insert"
  [1] "delete"
  [1] "end"
  [1] "pageup"
  [1] "pagedown"
  [1] "-"
  [1] "pageup"
  [1] "pagedown"
  [1] "-"
  [1] "home"
  [1] "end"
  [1] "-"
  [1] "f1"
  [1] "f2"
  [1] "f3"
  [1] "f4"
  [1] "-"
  [1] "f5"
  [1] "f6"
  [1] "f7"
  [1] "f8"
  [1] "f9"
  [1] "f10"
  [1] "f11"
  [1] "f12"
  [1] "-"
  [1] "f1"
  [1] "f2"
  [1] "f3"
  [1] "f4"
  [1] "-"
  [1] "escape"

nonblocking

Code
  p$write_input("cli::keypress(block = FALSE)\n")
  p$poll_io(1000)
Output
    output    error  process 
   "ready" "nopipe" "silent" 
Code
  cat(p$read_output())
Output
  [1] NA

Code
  p$write_input("{ Sys.sleep(0.5); cli::keypress() }\nX")
  p$poll_io(1000)
Output
    output    error  process 
   "ready" "nopipe" "silent" 
Code
  cat(p$read_output())
Output
  [1] "X"