A small script that demonstrates option parsing in Ruby.

optparse.rb

require 'optparse'

options = {}

# Create new options parser
OptionParser.new do |opt|

  # Set the help message banner
  opt.banner = "Usage: #{opt.program_name}.rb [options]"

  # Specify options and set the respective values in the options hash
  opt.on('-q','--quiet','Quiet mode') { |o| options[:quiet] = o }
  opt.on('-i','--interactive','Interactive mode') { |o| options[:interactive] = o }
  opt.on('-f FILENAME','--file FILENAME','Specifies filename') { |o| options[:filename] = o }

  # Set the options that show the help menu (created by OptionParser)
  opt.on('-h','--help','View the help menu') { puts opt; exit }

  # Show help menu if no arguments specified
  if ARGV.length == 0 then puts opt; exit end

  # Parse arguments and abort if exception
  begin
    opt.parse!
  rescue Exception => e
    abort e.message
  end

end

puts options
if options[:quiet] then puts "You're running in quiet mode!" end
if options[:interactive] then puts "Interactive mode activated!" end
if options[:filename] then puts "You specified a filename: #{options[:filename]}" end