Server

local modem = peripheral.wrap('back')


function send(chan,reply,m)
    modem.transmit(chan,reply,m)
end

function get(chan,tmout)--listener
    if tmout==nil then
    tmout=100000000000000000000000000000 --change to call event w/o timer
    end
    modem.open(chan) --opens port
    chk=modem.isOpen(chan) --checks to make sure it is open
        if chk==true then --will set listener
        --mm = os.pullEvent("modem_message")
        timeout = os.startTimer(tmout)
        while true do
            event = {os.pullEvent()}
            if event[1] == "modem_message" then
                --print'Worked'
                --print(event[1].." "..event[2].." "..event[3].." "..event[4].." "..event[5].." "..event[6])
                msg=event[5]
                returnchan=event[4]
                chan=event[3]
                break
                elseif event[1] == "timer" and event[2] == timeout then
                break
            end
        end

    end
    if chk==false then
        --send error# to screen
        print('Error 100: Failed to Bind Port '..chan..'.')
    end
end

function listen()
print'Listening...'
while true do
get(1)
--print(msg)
send(2,1,"ping")
--sleep(.5)
--os.reboot()
end

end
function test()
print'Welcome to Server 1.'
print'System online.'
print'Please make a choice:'
print'1: Shutdown'
print'2: Reboot'
print'3: Terminate'

ch=io.read()
ch=ch+1-1

if ch==1 then
print'Shutting down!'
sleep(1)
os.shutdown()
end

if ch==2 then
print'Rebooting!'
sleep(1)
os.reboot()
end

if ch==3 then
print'Terminating program!'
sleep(1)
term.clear()
term.setCursorPos(1,1)
end

end

parallel.waitForAny(test,listen)