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.




class
    APPLICATION
 
create
    make
 
feature {NONE} -- Initialization
 
    make
            -- Run application.
        do
            create input_file.make_open_read ("input.txt")
            create output_file.make_open_write ("output.txt")
 
            from
                input_file.read_character
            until
                input_file.exhausted
            loop
                output_file.put (input_file.last_character)
                input_file.read_character
            end
 
            input_file.close
            output_file.close
        end
 
feature -- Access
 
    input_file: PLAIN_TEXT_FILE
    output_file: PLAIN_TEXT_FILE
 
end