From: Brian Candler <b.candler@...>
Date: 2009-05-20T21:28:14+09:00
Subject: Re: optparse: Arguments as Arguments Unexpectedness

Ben Woodcroft wrote:
> I am trying to use the standard optionparser to read in some arguments,
> but one of those arguments is an argument itself. Is this a bug?

I don't think so. I think it's an ambiguity because you have declared 
your -a flag to take an *optional* argument.

Suppose your OptionParser also honoured the -d option. It would need to 
choose between "-a" with argument "-d me", and "-a" with no argument 
followed by option "-d" with argument "me". OptionParser is taking the 
view that anything which starts with a dash in that case is intended to 
be the next option on the line. Otherwise, the argument to the -a flag 
would hardly be optional if it always consumed the next string.

If your -a option *always* takes an argument, then declare it as such, 
without the square brackets:

require 'optparse'
OptionParser.new do |opts|
opts.on('-a','--args ARGUMENTS',String,"arguments") {|v| puts "Found:
#{v}"}
end.parse!

$ ruby opt.rb -a "-d me"
Found:
-d me

Otherwise, your original code works as long as you include the flag and 
its argument in the same position.

$ ruby opt.rb "-a-d me"
Found:
-d me
-- 
Posted via http://www.ruby-forum.com/.