NDesk.Options

NDesk.Options is a program option parser for C#.

See: http://www.ndesk.org/Options

Overview:

It takes advantage of C# 3.0 features such as collection initializers and lambda delegates to provide a short, concise specification of the option names to parse, whether or not those options support values, and what to do when the option is encountered. It's entirely callback based:

var verbose = 0;
var show_help = false;
var names = new List<string> ();

var p = new OptionSet () {
    { "v|verbose", v => { if (v != null) ++verbose; } },
    { "h|?|help",  v => { show_help = v != null; } },
    { "n|name=",   v => { names.Add (v); } },
};

However, C# 3.0 features are not required, and can be used with C# 2.0:

int          verbose   = 0;
bool         show_help = false;
List<string> names     = new List<string> ();

OptionSet p = new OptionSet ()
  .Add ("v|verbose", delegate (string v) { if (v != null) ++verbose; })
  .Add ("h|?|help",  delegate (string v) { show_help = v != null; })
  .Add ("n|name=",   delegate (string v) { names.Add (v); });

Distribution:

In accordance with the Guidelines for Application Deployment [0], there are pkg-config files to permit simple access to the source or pre-compiled assemblies for re-use.

There are two ways to use NDesk.Options:

- Bundle src/NDesk.Options/NDesk.Options/Options.cs with your app.

    pkg-config --variable=Sources ndesk-options

- Use a prebuilt NDesk.Options.dll:

    pkg-config --variable=Libraries ndesk-options

[0] http://www.mono-project.com/Guidelines:Application_Deployment#Libraries_with_Unstable_APIs