From: Nathaniel Talbott <nathaniel@...>
Date: 2003-07-19T01:31:43+09:00
Subject: Re: Usage Message for GetoptLong

Joey Gibson [mailto:joeygibson@earthlink.net] wrote:

> I've been wanting an easy way to output usage info for my 
> programs that use GetoptLong, without having to duplicate all 
> the option information; once for the creation of the 
> GetoptLong object, and again in a help message. I've taken a 
> crack at altering GetoptLong to support a "usage" method that 
> essentially does what I want. 
> 
> Basically what it does is have you include a fourth parameter for each
> option: the description. This is used internally, then 
> removed from each array, the collection is then passed to the 
> original initialize method for regular processing. Calling 
> the usage method of your GetoptLong object will print out a 
> user-defined message (or a default) and then iterates over 
> the options, printing both long and short versions, and the 
> description. I've included the code below in a test program. 
> I'm not finished with it, but I wanted to share it. I want to 
> make the output a little prettier and maybe make it more 
> flexible. I don't know yet. I welcome any suggestions or comments.

Well, you could try using optparse...

  require 'optparse'

  ARGV.options do |options|
    options.on('-d', '--date=DATE', String, 'specify a date'){|v| puts "Date
#{v} passed"}
    options.on('-q', '--quiet', 'be verry quiet'){puts "OK, I'm being very,
very, very quiet... can't you tell?"}
    options.on_tail('-h', '--help', 'Print this help information'){puts
options; exit}
    options.parse!
  end

I believe that's approximately equal to what you posted. I've only just
begun using optparse, but it seems quite powerful and easy to use.

HTH,


Nathaniel

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