How do I add a variable to the program execute?

I'm wondering how I could add a variable for when I execute my program.

For instance, you can execute "excavate 10", and it will excavate a 10x10 area.

Thanks for your help! :)/>

You catch the arguments passed in from the shell.

local args = {...} --put the arguments from the shell in a table
print(#args) --print the number of arguments that were passed in
print(args[1]) --print the first argument that was passed in