File input/output is part of Short Circuit's Console Program Basics selection.
Task

Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable.

In other words, your program will demonstrate:

   how to read from a file into a variable
   how to write a variable's contents into a file


Oneliners that skip the intermediate variable are of secondary interest — operating systems have copy commands for that.




 
inFile  = io.open("input.txt", "r")
data = inFile:read("*all") -- may be abbreviated to "*a";
                           -- other options are "*line", 
                           -- or the number of characters to read.
inFile:close()
 
outFile = io.open("output.txt", "w")
outfile:write(data)
outfile:close()
 
-- Oneliner version:
io.open("output.txt", "w"):write(io.open("input.txt", "r"):read("*a"))
 