[libcamera-devel] [PATCH] cam: options: optional arguments needs to be specified as --foo=bar

[Kieran Bingham]

Heya,

On 25/01/2019 11:23, Niklas Söderlund wrote:
> Hi Laurent,
> 
> On 2019-01-25 13:01:34 +0200, Laurent Pinchart wrote:
>> Hi Niklas,
>>
>> On Fri, Jan 25, 2019 at 12:23:11AM +0100, Niklas Söderlund wrote:
>>> It's not state in the documentation but optional arguments needs to be
>>> specified using as '--foo=bar' instead of '--foo bar', otherwise the
>>> value is not propagated to optarg during argument parsing. Update the
>>> usage printing helper to reflect this requirement.
>>>
>>> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
>>> ---
>>>  src/cam/options.cpp | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/src/cam/options.cpp b/src/cam/options.cpp
>>> index 82acff9bbeea476d..73d81d0bc0ec6d38 100644
>>> --- a/src/cam/options.cpp
>>> +++ b/src/cam/options.cpp
>>> @@ -143,7 +143,8 @@ void OptionsParser::usage()
>>>  		};
>>>  
>>>  		if (option.argument != ArgumentNone) {
>>> -			argument += std::string(" ");
>>> +			argument += option.argument == ArgumentOptional ?
>>> +				"=" : " ";
>>>  			if (option.argument == ArgumentOptional)
>>>  				argument += "[";
>>>  			argument += option.argumentName;
>>
>> This will output
>>
>> 	-f, --foo value
>>
>> for mandatory arguments, and
>>
>> 	-f, --foo=[value]
>>
>> for optional arguments. If we want to print the =, shouldn't it be
>> --foo[=value] ?
> 
> It should of course be --foo[=value], will fix.
> 
>> And how should we handle the case where no long option
>> is available, with this patch -f=[value] would be printed, which isn't
>> correct I think.
> 
> Good point, for optional short arguments the syntax would be -fvalue.  
> Would it make sens to print both short and long syntax in the usage?
> 
>     -f[value], --foo[=value]
> 
> Let me know what you think and I send a v2.

Is it difficult to accept a space or an = separator on the arguments?



-- 
Regards
--
Kieran