Readme.md

Command line arguments

The classes in this namespace provide an easy way for developers to create command line tools that can be invoked with rich command line arguments.

The ArgumentParser class is able to fill the properties of a complex configuration object with command line arguments provided by the caller.

Example

This is an example of a command line call to a tool that uses this parser technique for handling command line arguments:

SnBenchmark.exe -PROFILE:"Visitor:1+1" -SITE:"http://example.com" -WARMUP:20 -LIMIT:"Normal:4.0;Slow:8.0"

Usage from code

The ArgumentParser class is capable of parsing the arguments above and filling the provided config object's properties with the values.

In the following example MySetting is a custom object created by the developer to hold configuration information. It should contain properties annotated with any of the attributes found in the CommandLineArguments namespace (e.g. CommandLineArgumentAttribute).

var settings = new MySettings();
try
{
    var result = ArgumentParser.Parse(args, settings);
    if(result.IsHelp)
    {
        // settings' properties are not filled, display the usage screen and exit
        Console.WriteLine(result.GetHelpText());
    }
    else
    {
        // execute main logic with a filled config object
        Run(settings);		
    }
}
catch(ParsingException e)
{
    Console.WriteLine(e.FormattedMessage);
    Console.WriteLine(e.Result.GetHelpText());
}

Configuration class

The recommended design of this class is that you define private annotated properties for the parser to fill and expose the parsed information in public properties in a format required by your application (e.g. a string property that will be filled by the parser and a public property that exposes a list from that string). Of course if you work with only simple properties, you do not have to duplicate them.

public class MySettings
{
	public string[] SiteUrls { get; private set; }
	private string _siteUrlArg;

	[CommandLineArgument(name: "Site", required: true, aliases: "S", helpText: "Comma separated url list (e.g.: 'http://mysite1,http://mysite1').")]
        private string SiteUrlArg
        {
            get { return _siteUrlArg; }
            set
            {
                _siteUrlArg = value;
                SiteUrls = ParseSiteUrls(value);
            }
        }
}