root/trunk/examples/util/config/OptionGroups.d

/*******************************************************************************

    License:    Boost Software License, v. 1.0
                Academic Free License, v. 3.0
                BSD License

    Authors:    Marcin Kuszczak, www.zapytajmnie.com (author's christian site)
                This software is inspired and partially based on Boost C++
                library named 'program_options' and created by Vladimir Prus.

    Version:    0.9.1
    Date:       30-Apr-2008

    History:    0.9.0 (08-Oct-2007) -   initial public version

    Description:
                This example shows how to handle options groups.

                For a test, run:
                option_groups --help
                option_groups --num-threads 10
                option_groups --help-module backend

                The first invocation would show to option groups, and will not
                show the '--num-threads' options. The second invocation will
                still get the value of the hidden '--num-threads' option.
                Finally, the third invocation will show the options for the
                'backend' module, including the '--num-threads' option.

 ******************************************************************************/

import std.stdio;

import doost.util.config.ProgramOptions;
import doost.util.config.CommandLineStorage;

//------------------------------------------------------------------------------

/*******************************************************************************
    Program entry point
 ******************************************************************************/
void main(char[][] args) {
    try {
        // Declare three groups of options.
        auto general = new RegularOptions("General options");
        general.options()
            ("help", "produce a help message")
            ("help-module", define!(char[]), "produce a help for a given module")
            ("version", "output the version number")
            ;

        auto gui = new RegularOptions("GUI options");
        gui.options()
            ("display", define!(char[]), "display to use")
            ;

        auto backend = new RegularOptions("Backend options");
        backend.options()
            ("num-threads", define!(int), "the initial number of threads")
            ;

        // Declare an options description instance which will include
        // all the options
        auto all = new RegularOptions("Allowed options");
        all.add(general, gui, backend);

        // Declare an options description instance which will be shown
        // to the user
        auto visible = new RegularOptions("Allowed options");
        visible.add(general).add(gui);


        auto po =   (new ProgramOptions)
                        .next(
                    new CommandLineStorage(args, all)
                    );

        po.connect;

        auto formatter = new CommandLineFormatter;

        if ("help" in po) {
            writefln(visible.describe(formatter));
            return;
        }

        if ("help-module" in po) {
            char[] s = po["help-module"].as!(char[])();
            switch(s) {
                case "gui":     writefln(gui.describe(formatter)); break;
                case "backend": writefln(backend.describe(formatter)); break;
                default:        writefln("Unknown module '", s, "' in the --help-module option");
                                return 1;

            }
            return;
        }

        if ("num-threads" in po) {
            writefln("The 'num-threads' options was set to ", po["num-threads"].as!(int)());
        }

        po.disconnect;
    }

    catch(ProgramOptionsException e) {
        writefln(e);
    }
}