how to restart a lua program using the script in the lua script

It's me again

I'm trying to make a Terminal program in Lua since it's my best language I know, I'm making the calculator program in it and I'm trying to make it so if the user types "exit" the program will restart and will go back to the terminal, but I don't know how to reset the program through the code. if anyone can help that be deeply appreciated.

This is the code:

io.write("Terminal is starting up --- done!")
io.write("Making sure everything works --- Done!")
cmd = io.read()
io.write(">")

if cmd == "" then 
    io.write(">\n")
end

if cmd == "cal"then
    io.write("Calculator Terminal Program v1.0")
    io.write("what operation?/n")
    op = io.read()
    
    if op == "exit"then
        io.write("Exiting")
    end
end

To answer your question directly, I don't think it's possible to "restart the program". However, by taking advantage of loops, you can achieve the same result.

For instance, this code probably does what you want:

print('Terminal is starting up --- done!')
print('Making sure everything works --- Done!')

repeat
    io.write('>')
    cmd = io.read()

    if cmd == 'cal' then
        print('Calculator Terminal Program v1.0')
        repeat
            io.write('Operation: ')
            op = io.read()
        until op == 'exit'
        print('Exiting')
    elseif cmd == 'command' then
        --another command
    else
        print('Unknown command.')
    end

until cmd == 'exit'

Other tips:

• You should take advantage of elseif instead of writing multiple separate if statements to improve readability.
• Consider using the print function when you want a new line after writing some text for a better Terminal experience. You could also use io.write('\n').