Re: [boost] [program_options] option recognition is too permissive

From: Florent Teichteil (florent.teichteil_at_[hidden])
Date: 2008-05-22 12:35:07

On Thu, May 22, 2008 at 12:18 PM, Vladimir Prus
<vladimir_at_[hidden]> wrote:
> Florent Teichteil wrote:
>
>> Hi,
>>
>> I suggest to improve options' parsing error recognition, since
>> program_options does not throw an exception for command line options
>> that are substrings of actual options.
>>
>> To be clear : assume we add an option "myoption" with the
>> boost::program_options::options_description::add_options() function.
>>
>> The following command line options are recognized (program_options
>> does not throw an exception):
>> myoption [OK,should be recognized]
>> myopt [BAD,should not be recognized]
>>
>> The following command line options are not recognized (program_options
>> throws an exception):
>> myoptions [OK,should not be recognized]
>> myopr  [OK,should not be recognized]
>>
>> I suggest program_options should parse the entire option string until
>> reaching a '=' or ' ' character, and then trying to recognize this
>> option.
>
> This is by design. There's a style option 'allow_guessing' that's on by
> default, but you can always pass a different style to the parse_command_line
> function.
>
> - Volodya
>
>

Sorry, I did not noticed it in the documentation. Actually, it is only
mentioned in the reference. As the "allow_guessing" behavior is not
very usual, it should be helpful to mention it in the tutorial? Or at
least mention that one can change the behavior of the command line
parser?

Florent