Iters = 10000
N = 4
Meths = {
  :shuf   => "gshuf -i 0-#{N-1} -n 1",
  :seq    => "gseq 0 #{N-1} | gsort -R | head -n1",
  :urand1 => "echo $(($(printf '%d' \"'`head -c 1 /dev/urandom | base64 | tr A D`\")%4))",
  :urand2 => "echo $(($(printf '%d' \"'`head -c 1 /dev/urandom | base64`\")%4))"
}

def test(cmd)
  t = Time.now
  results = [0] * N
  1.upto(Iters) do
    i = `#{cmd}`.to_i
    results[i] += 1
  end
  puts(Time.now - t)
  results
end

Meths.each do |meth, cmd|
  print "[#{meth}]"
  test(cmd).each_with_index do |n, i|
    puts "    #{i}: #{n}"
  end
  puts
end