CODEWITHSUNDEEP
c#.netparsingcommand-linecommand-line-arguments
loonatic
loonatic

Reputation: 31

Parsing command line arguments using C# CommandLine library

I am using CommandLine library v 1.9.71.2 from nuget. Unfortunately documentation is not up to date and I don't understand advanced C# language constructions used for this library, so I couldn't come up with working solution just by watching interface available in library.

My options class looks like this:

class ProgramOptions
{
    [Option('l', "spotsL", Required = true, HelpText = "Lowest stock price used for calculations.")]
    public double lowestSpot { get; set; }

    [Option('h', "spotsH", Required = true, HelpText = "Highest stock price used for calculations.")]
    public double highestSpot { get; set; }

    [Option('n', "spotsN", Required = true, HelpText = "Number of (equally distributed) stock prices [spotsL,spotsH].")]
    public int spotsNumber { get; set; }

    [OptionList('m', "maturities", ',', Required = true, HelpText = "Comma separated list of options maturities (as a fraction of a year).")]
    public IList<string> maturities { get; set; } //we want double here.

    [Option('s', "strike", Required = true, HelpText = "Strike price of options.")]
    public double strikePrice { get; set; }

    [Option('v', "vol", Required = true, HelpText = "Volatility used for calculation.")]
    public double volatility { get; set; }
}

I need only long names of the options, but when I put null's (as documentation suggests) in place of short names I get compiler errors. I'd also prefer to have maturities as a list of doubles (IList<double> maturities), but IDK how to achieve this - i think with pure CommandLine it works only for list of strings.

Second part is that I can't parse options from command line args to the ProgramOptions object. Was trying something like:

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine(args[1]);
        ///Parse Command Line
        var options = new ProgramOptions();
        bool is_succes = Parser.Default.ParseArguments(args, options);
        Console.WriteLine("parsed? {0}",is_succes);

        Console.WriteLine(options.highestSpot);
        Console.WriteLine(options.lowestSpot);
        Console.WriteLine(options.maturities.ToString());
        Console.WriteLine(options.spotsNumber);
        Console.WriteLine(options.strikePrice);
        Console.WriteLine(options.volatility);
        Console.WriteLine("program working");
    }
}

Unfortunately it doesn't work and gives False in is_succes variable. All other variables display 0. My command line arguments were Any chance to get the library to parse something like:

/spotsL 10 /spotsH 1000 /spotsN 9 /maturities 1,0.5,0.001 /strike 495 /vol 0.1

and 10 is indeed displayed by te first WriteLine.

Upvotes: 3

Views: 4279

Answers (1)

AJ Richardson
AJ Richardson

Reputation: 6830

I'm not too familiar with the CommandLine library, but from a quick look at the documentation, it looks like you need to use a single dash (-) for single-character arguments or a double dash (--) for multiple-character arguments, i.e.

--spotsL 10 --spotsH 1000 --spotsN 9 --maturities 1,0.5,0.001 --strike 495 --vol 0.1

Edit: if you really need the input arguments to have slashes, you need to convert them to dashes:

public static void FormatArguments(string[] args)
{
    for (int i = 0; i < args.Length; i++)
        if (args[i].StartsWith("/"))
            args[i] = "--" + args[i].Substring(1);
}

Upvotes: 4

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