Standard I/O

One of Lune's most useful libraries for writing scripts is the standard I/O library, also known as stdio, which will be the first one we introduce here. The pages following this one will introduce several others.

Prompting for User Input

The easiest way to get started and being productive using Lune is to prompt the person running your script for some text input, which you can do using the stdio library. Let's make a script called hello.luau:

local stdio = require("@lune/stdio")
 
local name = stdio.prompt("text", "Hello there! What's your name?")
 
print("Hello, " .. name .. "!")

Now you can place this script in your current directory, and run it using Lune:

lune run hello

You can also prompt for more than just text. Let's extend the above script and ask the person running the script if that was really their name:

local confirmed = stdio.prompt("confirm", "Is that really your name?")
if confirmed then
	print("Nice to meet you, " .. name .. "!")
	print("Have a great day!")
else
	print("You lied to me! Goodbye 😡")
end

There are more options for prompting for user input than what we covered in this example, but these two basic prompting methods should cover most of your use cases and get you started with making interactive scripts.

Next, head on over to the following section on Script Arguments or check out the bonus game below!

local stdio = require("@lune/stdio")
 
print("")
print("Let's play a game! Whoever guesses the correct number between 1 and 10 first will win.")
print("")
 
local answer = tostring(math.random(1, 10))
 
local guess = stdio.prompt("text", "Input a number between 1 and 10")
while guess ~= answer do
	print("Incorrect! Computer's turn...")
 
	local computer = tostring(math.random(1, 10))
	print("The computer guessed", computer)
 
	if computer == answer then
		break
	end
 
	print("Incorrect! Your turn...")
	guess = stdio.prompt("text", "Input a number between 1 and 10")
end
 
print("")
print(if guess == answer then "You won the game! 🎉" else "The computer won the game! 😭")
print("")

lune run guessing-game