NFlags 1.0.0

NFlags

Simple library to made parsing CLI arguments easy. Library also allow You to print usage help "out of box".

For example of usage check Examples directory.

Basics

Set app name

Name set with folowing code, will be printed in help. By default AppDomain.CurrentDomain.FriendlyName is used.

NFlags.Configure(configurator => configurator.SetName("Custom Name"));

Set app description

Description set with folowing code, will be printed in help.

NFlags.Configure(configurator => configurator.SetDescription("App description"));

Set flag

Flag is an prefixed argument without value. It can be turned on or off. Flag abreviation can be also set.

NFlags.Configure(configurator => configurator.RegiasterFlag("flag", "f", "Flag description", () => flagVariable = true));
NFlags.Configure(configurator => configurator.RegiasterFlag("flag", "Flag description", () => flagVariable = true));

Set option

Option is an prefixed argument with value. Flag abreviation can be also set.

NFlags.Configure(configurator => configurator.RegiasterOption("option", "o", "option description", v => optionVariable = v));
NFlags.Configure(configurator => configurator.RegiasterOption("option", "option description", v => optionVariable = v));

Set parameter

Parameter is an unprefixed value argument. Parameters are read by registration order.

NFlags.Configure(configurator => configurator.RegiasterParam("param", "Param description", v => paramVariable = v));

Parsing arguments

To parse arguments call:

NFlags.Configure(configurator => {}).Read(args);

Dialects

Dialect defines how flags and options are prefixed and how option value follows option. By default 2 dialect are suported: Gnu, Win

Dialect can be set (default is Win) using:

NFlags.Configure(configurator => configurator.SetDialect(Dialect.Gnu));

Dialects can be easly extended. To create new dialect simply create new class inherited from Dialect class.

    public class CustomDialect : Dialect
    {      
        public override string Prefix => "x";

        public override string AbrPrefix => "a";

        public override OptionSeparator OptionSeparator => OptionSeparator.ArgSeparator;
    }

and configure NFlags using it

NFlags.Configure(configurator => configurator.SetDialect(new CustomDialect()));

Win dialect

Win dialect, follows MS Windows standards for definig console app arguments:

• Flags and flags abreviations are prefixed by '/'
• Options and options abreviations are prefixed by '/'
• Value follow option after '='

Gnu dialect

Gnu dialect, follows Gnu Linux standards for definig console app arguments:

• Flags are prefixed by '--'
• Flags abreviations are prefixed by '-'
• Options are prefixed by '--'
• Options abreviations are prefixed by '-'
• Value follow option as next argument after option

Help

Help generation is suported "out of box" and it follows dialect rules. To print help use:

Console.WriteLine(NFlags.Configure(configurator => {}).PrintHelp());

Example help for Win dialect:

Usage:
        NFlags.Win [FLAGS]... [OPTIONS]... [PARAMETERS]...

Application description

        Flags:
        /help, /h       Print this help
        /verbose, /v    Verbose description
        /clear  Clear description

        Options:
        /option1=<option1>, /o1=<option1>       Option 1 description
        /option2=<option2>      Option 2 description

        Parameters:
        <param1>        Parameter 1 description

and for Gnu dialect:

Usage:
        NFlags.Gnu [FLAGS]... [OPTIONS]... [PARAMETERS]...

Application description

        Flags:
        --help, -h      Print this help
        --verbose, -v   Verbose description
        --clear Clear description

        Options:
        --option1 <option1>, -o1 <option1>      Option 1 description
        --option2 <option2>     Option 2 description

        Parameters:
        <param1>        Parameter 1 description