.NET CLI Shebangs and Argument Parsing

I’ve been using the dotnet run app.cs CLI applications for a little while. Until now, I had no problem with arguments passed in, but today I added a -v option to my application to print out the version number.

Something like this -

#!/usr/bin/dotnet run 

foreach (string arg in args)
{
    switch (arg)
    {
        case "-v":
        case "--version":
            Console.WriteLine("Simple Application: Version 1.0.0");
            return;
    }
}  

When I run it with ./app.cs --version it works fine, but when I run it with ./app.cs -v I get an error -

Required argument missing for option: '-v'.

Description:
  .NET Run Command

Usage:
  dotnet run [<applicationArguments>...] [options]

//snip
  -v, -verbosity <LEVEL>                  Set the MSBuild verbosity level. Allowed values are q[uiet], 
                                          m[inimal], n[ormal], d[etailed], and diag[nostic].

For some reason, the dotnet run command is treating -v as an option for itself, rather than passing it through to the application. That is why it complains about a required argument missing for the -v option, which relates to verbosity in dotnet run.

If I run it with ./app.cs -- -v it is fine again, but I don’t want to have to do that every time.

I tried changing the shebang and found some that work and some that don’t.

Here are the ones that work -

1#!/usr/bin/dotnet --
2#!/usr/bin/env -S dotnet --
3#!/usr/bin/env -S dotnet run --

There, hope this helps someone or future me.