Easiest way to make lua script wait/pause/sleep/block for a few seconds?

Question

I cant figure out how to get lua to do any common timing tricks, such as

• sleep - stop all action on thread

• pause/wait - don\'t go on to the

Answer 1

I believe for windows you may use: os.execute("ping 1.1.1.1 /n 1 /w <time in milliseconds> >nul as a simple timer. (remove the "<>" when inserting the time in milliseconds) (there is a space between the rest of the code and >nul)

Answer 2

[I was going to post this as a comment on John Cromartie's post, but didn't realize you couldn't use formatting in a comment.]

I agree. Dropping it to a shell with os.execute() will definitely work but in general making shell calls is expensive. Wrapping some C code will be much quicker at run-time. In C/C++ on a Linux system, you could use:

static int lua_sleep(lua_State *L)
{
    int m = static_cast<int> (luaL_checknumber(L,1));
    usleep(m * 1000); 
    // usleep takes microseconds. This converts the parameter to milliseconds. 
    // Change this as necessary. 
    // Alternatively, use 'sleep()' to treat the parameter as whole seconds. 
    return 0;
}

Then, in main, do:

lua_pushcfunction(L, lua_sleep);
lua_setglobal(L, "sleep");

where "L" is your lua_State. Then, in your Lua script called from C/C++, you can use your function by calling:

sleep(1000) -- Sleeps for one second

Answer 3

require 'alien'

if alien.platform == "windows" then
  kernel32 = alien.load("kernel32.dll")
  sleep = kernel32.Sleep
  sleep:types{ret="void",abi="stdcall","uint"}
else
  -- untested !!!
  libc = alien.default
  local usleep = libc.usleep
  usleep:types('int', 'uint')
  sleep = function(ms)
    while ms > 1000 do
      usleep(1000)
      ms = ms - 1000
    end
    usleep(1000 * ms)
  end
end 

print('hello')
sleep(500)  -- sleep 500 ms
print('world')

Answer 4

cy = function()
    local T = os.time()
        coroutine.yield(coroutine.resume(coroutine.create(function()
    end)))
    return os.time()-T
end
sleep = function(time)
    if not time or time == 0 then 
        time = cy()
    end
    local t = 0
    repeat
        local T = os.time()
        coroutine.yield(coroutine.resume(coroutine.create(function() end)))
        t = t + (os.time()-T)
    until t >= time
end

Answer 5

You want  win.Sleep(milliseconds), methinks.

Yeah, you definitely don't want to do a busy-wait like you describe.

Answer 6

If you happen to use LuaSocket in your project, or just have it installed and don't mind to use it, you can use the socket.sleep(time) function which sleeps for a given amount of time (in seconds).

This works both on Windows and Unix, and you do not have to compile additional modules.

I should add that the function supports fractional seconds as a parameter, i.e. socket.sleep(0.5) will sleep half a second. It uses Sleep() on Windows and nanosleep() elsewhere, so you may have issues with Windows accuracy when time gets too low.