ruby で ARGV をうけるコマンドっぽいものを作ってみる | http://www.d-wood.com/blog/2014/05/15_6221.html

argv_cmd.rb

#!/usr/bin/ruby
require 'optparse'

# default options
USER      = 'Tom'
PASSWORD  = 'tomtom'
SERVER    = 'localhost'


OPTS = {}

OptionParser.new do |opt|
  begin
    opt.program_name = File.basename($0)
    opt.version      = '0.0.1'

    opt.banner = "Usage: #{opt.program_name} [options] file.csv"

    opt.separator ''
    opt.separator 'Examples:'
    opt.separator "    % #{opt.program_name} -u foo -p bar -s buzz file.csv"

    opt.separator ''
    opt.separator 'Specific options:'

    opt.on('-u USER', '--user', 'user') {|v| OPTS[:u] = v}
    opt.on('-p PASSWORD', '--password', 'password') {|v| OPTS[:p] = v}
    opt.on('-s SERVER', '--server', 'server') {|v| OPTS[:s] = v}

    opt.separator ''
    opt.separator 'Common options:'

    opt.on_tail('-h', '--help', 'show this help message and exit') do
      puts opt
      exit
    end
    opt.on_tail('-v', '--version', 'show program\'s version number and exit') do
      puts "#{opt.program_name} #{opt.version}"
      exit
    end

    opt.parse!(ARGV)
  rescue => e
    puts "ERROR: #{e}.\nSee #{opt}"
    exit
  end
end

if OPTS[:u] then user = OPTS[:u] else user = USER end
if OPTS[:p] then password = OPTS[:p] else password = PASSWORD end
if OPTS[:s] then server = OPTS[:s] else server = SERVER end
if ARGV[0] then file_name = ARGV[0] else raise 'ERROR: File not found' end

puts "#{server} #{user}:#{password} #{file_name}"