8 replies to this topic

[xXThunder607Xx]

Hello. I have been working on a project in computercraft for quite some time now, and I have run into a problem. My program uses rednet to request and send info to other computers, and when one of those computers is not on or isn't working, my program keeps waiting for a message, and often times messes me up. I was wondering if there was a way to, after say a couple of seconds, it would print "Computer is offline" or "no signal" and reboot itself. Any help or ideas would be greatly appreciated. Thanks in advance.

[Dog]

Since you're using rednet, you can specify a timeout for rednet.receive() like so...

local id, message = rednet.receive(3)

That would have rednet.receive() timeout after 3 seconds, then you could continue on with your code, taking into account that your receive timed out (your values will be nil) instead of receiving a response.

Edited by Dog, 15 February 2015 - 09:20 PM.

[xXThunder607Xx]

So I could do something like:

rednet.open(side)
local id,msg = rednet.receive(3)
  if msg == nil then
print("error")
else
   -- do stuff
end

Correct?

[Dog]

That *should* work. If, for some reason, msg is not nil after the timeout (it should be, iirc), then you could use id instead...

if id == nil then

Edited by Dog, 16 February 2015 - 12:39 AM.

[Bomb Bloke]

I'd use "if type(message) ~= "string" then", or whatever type you're expecting.

[xXThunder607Xx]

Thanks guys. This helped alot.

[GreenGene]

local amount = 5  --wait time
local evnt = { rednet.receive( amount ) }
if evnt[ 1 ] ~= nil and evnt[ 2 ] ~= nil and evnt[ 3 ] ~= nil then
	--code to run if message received.
else
	print(  "Print computer offline" )
end

Edited by GreenGene, 19 April 2015 - 05:31 PM.

[flaghacker]

You forgot the {} around rednet.receive . And why wouldn't only checking one of the arguments work?

Edited by flaghacker, 11 April 2015 - 03:42 PM.

[GreenGene]

flaghacker, on 11 April 2015 - 03:41 PM, said:

You forgot the {} around rednet.receive . And why wouldn't only checking one of the arguments work?

Woops ur right I was in a hurry! XD