[Ruby] optparse template

optparse-sample.rb

#!/usr/bin/env ruby
# coding: utf-8
  
require 'optparse'
params   = ARGV.getopts('f:')
prg_name = File.basename(__FILE__)

  usage = <<-EOS
-------------------------
  Usage: parse [options]
      -f FileName
-------------------------
  EOS
end
  
if params['f'].nil?
  puts usage
else
  if not File.exists?(params['f'])
    puts "[Error][#{prg_name}]: No such file: #{params['f']}"
    puts usage
  end
end

# see also) http://qiita.com/genta/items/785900055a5be2ba5d2c