Re: [Boost-users] Boost program option parsing issue.

Subject: Re: [Boost-users] Boost program option parsing issue.
From: Vivek Anand (vickywindwin_at_[hidden])
Date: 2013-09-07 02:34:58

Thanks Tarcisio, This worked for me.

On Thu, Aug 22, 2013 at 9:06 PM, Tarcisio Fedrizzi
<tarcisio.fedrizzi_at_[hidden]> wrote:
> Hi,
> this does the trick:
>
> ( "input-file", po::value<string>(&inputFile)->implicit_value(""), "input
> file name" )
>
> note the implcit_value call added.
> In this way the parse works as you need.
>
> Best regards,
> Tarcisio Fedrizzi
>
>
> On Thu, Aug 22, 2013 at 3:58 PM, Vivek Anand <vickywindwin_at_[hidden]> wrote:
>>
>> On Thu, Aug 22, 2013 at 5:58 PM, Tarcisio Fedrizzi
>> <tarcisio.fedrizzi_at_[hidden]> wrote:
>> >
>> > Hi,
>> > why would you need to run the program with --input-file without a value?
>>
>> A third-party client will be using my program through a script or
>> through exec(). I do not have control over that code.
>>
>> Currently, my validation check throws error that output-file not
>> specified. Actually its the input file which is missing.
>>
>> >
>> > If you want to set the inputFile variable to a default value if it is
>> > not specified
>> > on the command line simply assign it where you declare the variable.
>> > Alternatively
>> > you can assign the variable like this:
>> >
>> > if (vm.count("input-file")) {
>> > ...
>> > } else {
>> >   inputFile = "whatever";
>> > }
>> >
>> > Best regards,
>> > Tarcisio Fedrizzi
>> >
>> >
>> >
>> > On Mon, Aug 19, 2013 at 6:46 PM, Vivek Anand <vickywindwin_at_[hidden]>
>> > wrote:
>> >>
>> >> Hi All,
>> >>
>> >> I am using program option for my program. Here is my code snippet
>> >>
>> >>  string inputFile, outputFile;
>> >>
>> >> /* Populate command line arguments */
>> >>     po::options_description desc("Usage: KDMGenerator [OPTIONS]");
>> >>     {
>> >>         desc.add_options()
>> >>             ("help", "prints this message")
>> >>             ( "input-file", po::value<string>(&inputFile), "input file
>> >> name" )
>> >>             ( "output-file", po::value<string>(&outputFile), "output
>> >> file name");
>> >>     }
>> >>
>> >>     po::variables_map vm;
>> >>     po::store(po::parse_command_line(argc, argv, desc), vm);
>> >>     po::notify(vm);
>> >>
>> >>     if (vm.count("help") || !vm.size())
>> >>     {
>> >>         cout <<desc;
>> >>         return 0;
>> >>     }
>> >>
>> >>     if(vm.count("input-file"))
>> >>     {
>> >>         cout << "Input file :" << inputFile << '\n';
>> >>     }
>> >>
>> >>     if(vm.count("output-file"))
>> >>     {
>> >>         cout << outputFile << '\n';
>> >>     }
>> >>
>> >>
>> >> The issue I am facing is that if i I call my program without passing
>> >> value for input file, something like
>> >>
>> >> ./myapp --input-file --output-file out.txt
>> >>
>> >> I get Input file: --output-file
>> >>
>> >>
>> >> i.e the value "--output-file" get stored in inputFile and
>> >> vm.count("output-file") returns zero.
>> >>
>> >> Is this the desired behavior? Is there any workaround for this?
>> >>
>> >> --
>> >> Vivek,
>> >>
>> >>
>> >> _______________________________________________
>> >> Boost-users mailing list
>> >> Boost-users_at_[hidden]
>> >> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>> >
>> >
>> >
>> > _______________________________________________
>> > Boost-users mailing list
>> > Boost-users_at_[hidden]
>> > http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>>
>>
>>
>> --
>> Warm regards ,
>> Vivek,
>> (¨`·.·´¨) Always
>> `·.¸(¨`·.·´¨) Keep Smiling
>> (¨`·.·´¨)¸.·´ N Be Happy!!
>> `·.¸.·´
>> _______________________________________________
>> Boost-users mailing list
>> Boost-users_at_[hidden]
>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>
>
>
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users

-- 
Warm regards ,
Vivek,
(¨`·.·´¨) Always
`·.¸(¨`·.·´¨) Keep Smiling
(¨`·.·´¨)¸.·´ N Be Happy!!
`·.¸.·´