program_options/example/option_groups.cpp
2015-02-15 21:41:48 +03:00

98 lines
3.0 KiB
C++

// Copyright Vladimir Prus 2002-2004.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
/** 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.
*/
#include <boost/program_options/options_description.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/program_options/variables_map.hpp>
#include <boost/tokenizer.hpp>
#include <boost/token_functions.hpp>
using namespace boost;
using namespace boost::program_options;
#include <iostream>
#include <fstream>
#include <exception>
using namespace std;
int main(int ac, char* av[])
{
try {
// Declare three groups of options.
options_description general("General options");
general.add_options()
("help", "produce a help message")
("help-module", value<string>(),
"produce a help for a given module")
("version", "output the version number")
;
options_description gui("GUI options");
gui.add_options()
("display", value<string>(), "display to use")
;
options_description backend("Backend options");
backend.add_options()
("num-threads", value<int>(), "the initial number of threads")
;
// Declare an options description instance which will include
// all the options
options_description all("Allowed options");
all.add(general).add(gui).add(backend);
// Declare an options description instance which will be shown
// to the user
options_description visible("Allowed options");
visible.add(general).add(gui);
variables_map vm;
store(parse_command_line(ac, av, all), vm);
if (vm.count("help"))
{
cout << visible;
return 0;
}
if (vm.count("help-module")) {
const string& s = vm["help-module"].as<string>();
if (s == "gui") {
cout << gui;
} else if (s == "backend") {
cout << backend;
} else {
cout << "Unknown module '"
<< s << "' in the --help-module option\n";
return 1;
}
return 0;
}
if (vm.count("num-threads")) {
cout << "The 'num-threads' options was set to "
<< vm["num-threads"].as<int>() << "\n";
}
}
catch(std::exception& e) {
cout << e.what() << "\n";
}
}