Ruby append to file

---

examples/files/append_to_file.rb

if ARGV.length != 1
  puts "Usage: #{$0} FILENAME"
  exit
end

filename = ARGV[0]
File.write(filename, 'My second line\n', mode: 'a')

examples/files/append.rb

File.open("data.txt", "a") do|fh|
  fh.puts "Hello"
end