From: botp <botpena@...>
Date: 2012-05-16T14:23:29+09:00
Subject: Re: Option Parser with an optional flag/switch for last argument

On Wed, May 16, 2012 at 5:56 AM, Neubyr Neubyr <lists@ruby-forum.com> wrote:
> Thanks for the reply everyone. I am taking approach as suggested by
> Bartosz and Chad to assign 'left-over' ARGV to the input decimal number.
>
> @Mike, the commandable gem looks really useful. I am not using it right
> now, but it looks like it will be useful in some of my other
> projects/command-line apps. Thanks for providing a detailed example.

if you need flexibility, then ARGV by itself is more than enough.

eg, re your sample,
$ cat -n test2.rb
     1	
     2	operator=ARGV.shift
     3	
     4	ops=%w(* / + -)
     5	
     6	if not (ops).include? operator
     7	  raise "operator argument must be one of #{ops}"
     8	end
     9	
    10	factors=ARGV
    11	if factors.size < 2
    12	  raise "need at least two args for operator"
    13	end
    14	
    15	factors=ARGV.map(&:to_f)
    16	
    17	p factors.inject(operator.to_sym)
    18	
    19	
botp@u:~
$ ruby test2.rb - 3 4 5  #subtract
-6.0
botp@u:~
$ ruby test2.rb + 3 4 5  #add
12.0
botp@u:~
$ ruby test2.rb "*" 3 4 5  #multiply; need to quote
60.0

just a thought.
kind regards -botp