Trying to communicate with beanstalkd

#!/usr/bin/env luajit

local fn = "/tmp/ffsock"
--Trying to connect to running beanstalkd
os.execute("socat -d -d -d pty,link="..fn..",raw  tcp:localhost:11300")
os.execute("sleep 1")
local writer = io.open(fn,"w")
local reader = io.open(fn,"r")
writer:write("invalidcommand\r\n")
writer:flush()
local txt = reader:read("*l")
print("Got response: "..txt)