CommandLineParser Documentation

In VB.NET, decorate option classes with <CommandLine.Verb(...)>. Use CommandLine.Parser.Default.ParseArguments(Of T1, T2, ...)(args) and .MapResult to handle the different verb types.

<CommandLine.Verb("add", HelpText:="Add file contents to the index.")>
Public Class AddOptions
    'Normal options here
End Class
<CommandLine.Verb("commit", HelpText:="Record changes to the repository.")>
Public Class CommitOptions
    'Normal options here
End Class
<CommandLine.Verb("clone", HelpText:="Clone a repository into a new directory.")>
Public Class CloneOptions
    'Normal options here
End Class

Function Main(ByVal args As String()) As Integer
    Return CommandLine.Parser.Default.ParseArguments(Of AddOptions, CommitOptions, CloneOptions)(args) _
          .MapResult(
              (Function(opts As AddOptions) RunAddAndReturnExitCode(opts)),
              (Function(opts As CommitOptions) RunCommitAndReturnExitCode(opts)),
              (Function(opts As CloneOptions) RunCloneAndReturnExitCode(opts)),
              (Function(errs As IEnumerable(Of [Error])) 1)
          )
End Function

To implement basic command line parsing in C#, define a class to hold your options decorated with the [Option] attribute, then use Parser.Default.ParseArguments<T> to parse the arguments and handle the result using .WithParsed<T>.

using System;
using CommandLine;

namespace QuickStart
{
    class Program
    {
        public class Options
        {
            [Option('v', "verbose", Required = false, HelpText = "Set output to verbose messages.")]
            public bool Verbose { get; set; }
        }

        static void Main(string[] args)
        {
            Parser.Default.ParseArguments<Options>(args)
                   .WithParsed<Options>(o =>
                   {
                       if (o.Verbose)
                       {
                           Console.WriteLine($"Verbose output enabled. Current Arguments: -v {o.Verbose}");
                           Console.WriteLine("Quick Start Example! App is in Verbose mode!");
                       }
                       else
                       {
                           Console.WriteLine($"Current Arguments: -v {o.Verbose}");
                           Console.WriteLine("Quick Start Example!");
                       }
                   });
        }
    }
}