Easy question: Read file, reverse it and write to another file in Ruby

Question

I have:

 o = File.new("ouput.txt", "rw+")
 File.new("my_file.txt").lines.reverse_each { |line|
       ?????  line 
 }
 o.close

I don't know what method to use to write to the file output o

Answer 1

puts understands arrays, so you can simplify this to:

File.open("f2.txt","w") {|o| o.puts File.readlines("f1.txt").reverse}