Class: Ziltoid::CommandParser

Inherits:
Object
  • Object
show all
Defined in:
lib/ziltoid/command_parser.rb

Constant Summary collapse

ALLOWED_COMMANDS = 
["watch", "start", "stop", "restart"]

Class Method Summary collapse

Class Method Details

.parse(args) ⇒ Object

Returns a structure describing the options.



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# File 'lib/ziltoid/command_parser.rb', line 10

def self.parse(args)
  runnable = OpenStruct.new

  helptext = <<-HELP
    Available commands are :
       watch :       watches all processes
       start :       starts all processes
       stop  :       stops all processes
       restart :     restarts all processes
  HELP

  opt_parser = OptionParser.new do |opts|
    # Printing generic help at the top of commands summary
    opts.banner = "Usage: ziltoid.rb [options]"
    opts.separator ""
    opts.separator helptext
    opts.separator ""
    opts.separator "Common options :"

    # No argument, shows at tail. This will print a commands summary.
    opts.on_tail("-h", "--help", "Show this message") do
      puts opts
      exit
    end
  end

  # Retrieves all arguments except option-like ones (e.g. '-h' or '-v')
  opt_parser.parse!(args)
  # Fetches the first argument as the intended command
  command = args.shift

  # Making sure the command is valid, otherwise print commands summary
  if command && ALLOWED_COMMANDS.include?(command)
    runnable.command = command
  else
    puts opt_parser.help
    exit
  end

  runnable
end