Directives

Directives are special arguments enabling cross cutting features. We've loosely followed the pattern defined by System.CommandLine to start with two directives, Debug & Parse.

Directives are a great way to add troubleshooting tools to your application. See Custom Directives at the bottom of this page for tips on adding your own.

How to use

Directives must be the first arguments, enclosed by square brackets and will be removed from the arguments list during tokenization. After the first non-directive token is processed, any following tokens with square brackets will be processed as commands and operand values.

dotnet example.dll [some-directive] -v [not-a-directive]

To disable the directives feature entirely, set AppSettings.DisableDirectives = true. This is only needed if an application has starting arguments enclosed by square brackets and using the argument separator is not a suitable solution.

Custom directives

Directives are middleware components.
See the implementations of Debug and Parse directives for examples.

The presence of a directive is checked with commandContext.Tokens.TryGetDirective("debug", out _)). The out parameter will include the entire string within the square brackets. Using a possible logging directive [log:debug], the out parameter value would be log:debug. You can parse the value however you'd like.