From: Stephan Wehner <stephanwehner@...>
Date: 2009-05-29T01:38:38+09:00
Subject: Re: OptionParser: unexpected behaviour with -help

Eric Hodel wrote:
> On May 23, 2009, at 21:58, Stephan Wehner wrote:
> 
>> I don't think that '-help' should be treated the same as '-h -ex lp'  
>> or
>> '-h --ex lp'. In particular, '-help' may be a misspelling of the
>> common  '--help' option. Am I doing something wrong? Is there a way to
>> avoid this?
> 
> When you use - instead of -- you invoke short-option-parsing like:
> 
> $ ruby -dvrubygems -e 'raise rescue nil'
> ruby 1.8.6 (2008-08-11 patchlevel 287) [universal-darwin9.0]
> Exception `LoadError' at /Library/Ruby/Site/1.8/rubygems.rb:1106 - no
> such file to load -- rubygems/defaults/operating_system
> Exception `LoadError' at /Library/Ruby/Site/1.8/rubygems/
> config_file.rb:35 - no such file to load -- Win32API
> Exception `RuntimeError' at -e:1 -
> $
> 
> Which is equivalent to:
> 
> ruby -d -v -r ubygems -e 'raise rescue nil'

There is some precedence for disabling this kind of command line 
parsing, see

  http://jargs.sourceforge.net/doc/api/jargs/gnu/CmdLineParser.NotFlagException.html

  http://tinyurl.com/notflagexception

Quote:

  public static class CmdLineParser.NotFlagException
  extends CmdLineParser.UnknownOptionException

  Thrown when the parsed commandline contains multiple concatenated 
short options, such as -abcd, where one or more requires a value. 
getMessage() returns an english human-readable error string.

End quote

This looks like a useful option to support.

Stephan

-- 
Posted via http://www.ruby-forum.com/.