function readln(rC)
 local s,si="",os.getenv("sI")
 while true do
  _,sI,c,C = event.pull("key")
  if sI == si then
   if c == 13 then
    write(" \n")
    coroutine.yield()
    return s
   elseif c == 8 then
    if s:len()>0 then s=s:sub(1,-2) write("\127") end
   elseif c > 31 and c < 127 then
    s=s..string.char(c) write((rC or string.char(c)))
   end
  end
 end
end