N MOD M(CodeEval)

CHALLENGE DESCRIPTION:

Given two integers N and M, calculate N Mod M (without using any inbuilt modulus operator).

INPUT SAMPLE:

Your program should accept as its first argument a path to a filename. Each line in this file contains two comma separated positive integers. E.g.

20,6
2,3

You may assume M will never be zero.

OUTPUT SAMPLE:

Print out the value of N Mod M

My Code

#!/usr/bin/env ruby -w

ARGF.each_line do |line|
  n, m = line.chomp.split(',').map(&:to_i)
  puts n.modulo(m)
end