Modem API

function send(ch,repch,msg,side)
        peripheral.call(side,"transmit",ch,repch,msg)
end

function receive(side,ch,timeout)
        local timeoutID = os.startTimer(timeout)
        for i,j in pairs(sides) do
                for k,v in pairs(ch) do
                    peripheral.call(j,"open",v)
                end
            end
        local function close()
            for i,j in pairs(side) do
                for k,v in pairs(ch) do
                    peripheral.call(j,"close",v)
                end
            end
        end
        while true do
                local evt,p1,p2,p3,p4,p5 = os.pullEvent()
                if(evt == "modem_message" and p2 == ch) then close() return p1,p2,p3,p4,p5 end
                if(evt == "timer" and p1 == timeoutID) then close() return nil end
        end
end