pty.lua

local ffi = require('ffi')
local uv = require('uv')
local wrapStream = require('coro-channel').wrapStream
local wrapRead = require('coro-channel').wrapRead
local split = require('coro-split')

ffi.cdef[[
  struct winsize {
      unsigned short ws_row;
      unsigned short ws_col;
      unsigned short ws_xpixel;   /* unused */
      unsigned short ws_ypixel;   /* unused */
  };
  int openpty(int *amaster, int *aslave, char *name,
              void *termp,
              const struct winsize *winp);
]]

local master = ffi.new("int[1]")
local slave = ffi.new("int[1]")
local name = ffi.new("char[1024]")
local winp = ffi.new("struct winsize")
winp.ws_row = 24
winp.ws_col = 80

-- Create the pty
ffi.C.openpty(master, slave, name, nil, winp)

-- Convert to lua values, freeing the ffi values.
master, slave, name = master[0], slave[0], ffi.string(name)

p {
  master = master,
  slave = slave,
  name = name
}

uv.spawn("/bin/stty", {
  args = {"-a"},
  stdio = {slave, slave, slave}
}, function (...)
  p("onexit", ...)
end)

local pipe = uv.new_pipe(false)
pipe:open(master)

pipe:read_start(function (err, data)
  assert(not err, err)
  print(data)
end)

uv.run()
uv.tty_reset_mode()

Sample Output:

{ slave = 26, master = 27, name = '/dev/ttys046' }
speed 9600 baud; 24 rows; 80 columns;
lflags: icanon isig iexten echo echoe -echok echoke -echonl echoctl
    -echoprt -altwerase -noflsh -tostop -flusho -pendin -nokerninfo
    -extproc
iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8
    -ignbrk brkint -inpck -ignpar -parmrk
oflags: opost onlcr -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow
    -dtrflow -mdmbuf
cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = <undef>;
    eol2 = <undef>; erase = ^?; intr = ^C; kill = ^U; lnext = ^V;
    min = 1; quit = ^\; reprint = ^R; start = ^Q; status = ^T;
    stop = ^S; susp = ^Z; time = 0; werase = ^W;

'onexit'    0   0