RE: Break out of program in interpreter

[Thijs Schreijer <thijs@...>]

> -----Original Message-----
> From: lua-l-bounces@lists.lua.org [mailto:lua-l-bounces@lists.lua.org] On
> Behalf Of Jose Torre-Bueno
> Sent: dinsdag 14 mei 2013 16:36
> To: Lua mailing list
> Subject: Re: Break out of program in interpreter
> 
> 
> > while true do os.execute('echo hello world') end
> >
> > cannot be stopped with ^C.
> 
> Thanks everybody you explained the question.  Now a somewhat related
> question:
> 
> Is there any way to pause a lua program for less than one second?
> 
> Thanks to your help I can write a loop like this:
> 
> while true do
> 	condition_met = some_function_that_should_no_be_done_too_often()
> 	if condition_met or not os.execute('sleep 1') then break end
> end
> 
> Which will end the loop if either the condition is met or the user gets
> bored and hits ^C
> 
> Obviously if the other function were lua I could use coroutines but if the
> other function is a separate program I am calling with os.execute and it
> uses significant system resources to do its checking I need some way to
> wait a reasonable time before calling it again.
> 
> Is there any way to make this time less than one second?
> 

For a quick and dirty fix to this I have a script that uses LuaSocket. Creates a fake socket, and then listens on that socket with a timeout of x seconds. If set to 0.1 second timeout, it will block for that period.

In another (slightly more complex) one I used Copas and CopasTimer. Create a fake socket, let copas listen on that, and use CopasTimer to create timers to be executed at any interval.

Thijs