Home

Quick Start

Using the CommandLineParser is intuitive. This Quick Start covers the basics, for detailed information and advanced topics see the links on the right.

Let's say you want to support

1. a switch (-s or --show)
2. an argument which requires a value of type decimal (-v 1.0 or --version 1.0)
3. an argument which allows to choose from 3 predefined values: red, green or blue (-c red or --color red) (For detailed information about argument types and settings, see Argument Types)

Setup

CommandLineParser.CommandLineParser parser = 
    new CommandLineParser.CommandLineParser();
SwitchArgument showArgument = new SwitchArgument(
    's', "show", "Set whether show or not", true);
ValueArgument<decimal> version = new ValueArgument<decimal>
    'v', "version", "Set desired version");
EnumeratedValueArgument<string> color = new EnumeratedValueArgument<string>
    'c', "color", new string[] { "red", "green", "blue" });
parser.Arguments.Add(showArgument);
parser.Arguments.Add(version);
parser.Arguments.Add(color);

Parsing arguments

In your main method, you can parse the arguments:

public static void main(string[] args) {
    CommandLineParser.CommandLineParser parser; 
    // set up the parser here as above...  
    parser.ParseCommandLine(args); 
    // access the values 
    if (color.Parsed) /// test, whether the argument appeared on the command line
    {
        var c = color.Value; //contains value of the level argument
    }  
}

Show Usage

You might want to show an overview of all the arguments your application supports. This is very easy, the following code: '''csharp parser.ShowUsageHeader = "Here is how you use the app: "; parser.ShowUsageFooter = "Have fun!"; parser.ShowUsage(); ''' will print:

Here is how you use the app:
Usage:
        -s, --show [optional] ... Set whether show or not
   
        -v, --version [optional] ... Set desired version

        -c, --color [optional] ...
Have fun!

You can also add long descriptions, use resource files to store them (see Resources) and even use localization (see Localization). You can also tell the parser to print the Usage info automatically when no arguments are supplied (see ShowUsageOnEmptyCommandline property). Usage info is also printed when the user uses --help, /? or /help argument.

Attributes & declarative syntax

You can create a custom class to hold all your argument values in fields or properties which you decorate with attributes - CommandLineParser will take care of extracting the information and populating the values.

class ParsingTarget
{
    [SwitchArgument('s', "show", true, Description = "Set whether show or not")]
    public bool show;

    [ValueArgument(typeof(decimal), 'v', "version", Description = "Set desired version")]
    public decimal version;

    [EnumeratedValueArgument(typeof(string),'c', "color", AllowedValues = "red;green;blue")]
    public string color;
}

...

ParsingTarget p = new ParsingTarget();
parser.ExtractArgumentAttributes(p);
parser.ParseCommandLine(args);

// all arguments are now stored in parsing target
if (p.version > 2)
{
   ... 
}

See Attributes & declarative syntax for more details on declarative syntax.

Extensibility

The library offers a set of argument types which will cover the most use cases, but you can extend it with your own type of attributes. See Extensibility & Custom Arguments on how to do that.

Combinations of attributes

CommandLineParser can be set up so that only certain combination of attributes are valid. You can do this with ArgumentCertification. This will even be reflected in ShowUsage command. See Combinations of arguments for details.