copas looping issue while connecting the server

[pritammore]

Hi,
I am new to lua programming and trying to implement Lua-websocket in openwrt as a client.
Was trying to use client copas library but the issue is the script is getting stopped listening server after executing once (i.e. connecting to server, receiving message, sending message). I want the script to always listen the server without any timeout or script halt.
Below is the script

local copas = require'copas'
local websocket = require'websocket'
local json = require('json')
local client = require 'websocket.client'.new()

local ok,err = client:connect('ws://192.168.1.250:8080')
if not ok then
print('could not connect',err)
end

local ap_mac = { command = 'subscribe', channel = 'test' }
local ok = client:send(json.encode(ap_mac))
if ok then
print('msg sent')
else
print('connection closed')
end

local message,opcode = client:receive()
if message then
print('msg',message,opcode)
else
print('connection closed')
end

local replymessage = { command = 'message', message = 'TEST' }
local ok = client:send(json.encode(replymessage))
if ok then
print('msg sent')
else
print('connection closed')
end

copas.loop()

Here copas.loop() is not working.

On openWrt I had installed lua 5.1
Any help would be appreciated.