Started by redstone [lua help]

I need to create a program for a game im making. its a jumping puzzle and once you hit a button it will activate a countdown on a computer. that countdown will keep the door open but once it hits zero will close the door. Now i may be very noobish at this but i know how to do the countdown and the redstone and all that. except i want to know how i can get a program to activate from a redstone signal.

Also if anyone knows how i can display numbers on a monitor straight from a program without typing

monitor (Direction) [program name]

I really appreaciate the help.

To start with redstone, you can make the program wait for it:

while true do
  os.pullEvent("redstone") -- wait for change in redstone
  if rs.getInput("<side>") then -- check the input on the side you want
	break -- break the loop and start the program
  end
end

-- your program here

For the monitor, you need the peripheral and term apis:

local mon = peripheral.wrap("<side>") -- get the monitor, replace <side> with the side of the monitor
term.redirect(mon) -- redirect the output to the monitor

-- your program here

term.restore() -- restore the output to the terminal

Great it works perfectly! thank you.

You could allso use shell.run(programPath) before the brake to make it two programs