From: "ara.t.howard" <ara.t.howard@...>
Date: 2008-07-03T13:01:37+09:00
Subject: Re: Lost with OptionParser


On Jul 2, 2008, at 6:54 PM, Greg Willits wrote:

> I'm having a real problem understanding OptionParser -- the docs in
> pickaxe are rather cryptic, Ruby Way doesn't even talk about it, and  
> all
> the Q&A I can find on the web doesn't clear it up for me.
>
> I've gotten this far:
>
> # test.rb ---------
> require 'optparse'
>
> commands = OptionParser.new
> commands.on("-h", "--help")   # more or less, I get the .on stuff
> commands.on("-e=RUN_ENV")
>
> commands.parse(ARGV)
>
> puts commands
>
> # ---------
>
> That will dump a display of the commands, but for the life of me, I
> can't figure out how to determine which options were actually  
> submitted.
> And if the -e param was supplied, what's its value is.
>
> I have seen:
>
>  commands.parse(ARGV)
>  commands.parse!(ARGV)
>  options = commands.parse(ARGV)
>
> So, confused by that to start with, then really confused by where the
> parsed commands are, and what format they're in.
>
> -- gw
> -- 
> Posted via http://www.ruby-forum.com/.
>



cfp:~ > cat a.rb
require 'yaml'
require 'rubygems' ### gem install rubygems
require 'main'

Main {
   option('environment', 'e'){
     synopsis 'specify run time environment'
     default 'development'
     argument :required
     validate{|arg| %w[ production development test ].include? arg}
   }

   def run
     environment = params['environment']

     y :given => environment.given?,
       :value => environment.value
   end
}



cfp:~ > ruby a.rb
---
:value: development
:given:


cfp:~ > ruby a.rb --environment=foobar
invalid: option(--environment)="foobar"

cfp:~ > ruby a.rb --environment=test
---
:value: test
:given: true



cfp:~ > ruby a.rb --help
NAME
   a.rb

SYNOPSIS
   a.rb [options]+

DESCRIPTION
   main.rb takes the pain of argument parsing away

PARAMETERS
   specify run time environment
   --help, -h



the packages ships with a tons of examples.

a @ http://codeforpeople.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama