Non-stopping input (even special characters, arrows etc.)

read_char.rb

require 'io/wait'

def read_char
  system "stty raw -echo"
  if $stdin.ready?
    char = $stdin.getc.chr
    if char == "\e"
      extra_thread = Thread.new do
        char += $stdin.getc.chr
        char += $stdin.getc.chr
      end
      extra_thread.join 0.0001
      extra_thread.kill
    end
  end
  char
end

# Example usage
def show_single_key
  char = read_char
  # Read char only if not nil
  # To make it non-stopping simply allow nil
  if char
    if char == "\u0003"
      system "stty -raw echo"
      puts "CHAR: #{char.inspect}"
      Process.exit! true
    else
    system "stty -raw"
    puts "CHAR: #{char.inspect}"
    end
  end
end

loop do
  show_single_key
end