Gracefully stop a program?

I'm running a tunnel program, and I want to stop the program when I run out of a particular item.

I currently have 12 slots allocated to wood, 3 slots for glass, and 1 for torches. When I run out of wood, glass, or torches - I want the program to stop.

How do you stop a program gracefully?

I am basically doing something like this:

if turtle.getItemCount(12) < 1 then
stop
end

What is the key word to stop a program?

error() will quit the program silently from any point in the code. To display a message without the usual error and line number prefixes, you can do, ex, error("Out of glass!",0). the 0 is important, and prevents displaying the line number.

That's even better than what I wanted! Thanks! Awesome idea.