【boost学习笔记】命令行解析库（program_options）

代码：

// 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)

/* The simplest usage of the library.
 */

#include <boost/program_options.hpp>
namespace po = boost::program_options;

#include <iostream>
#include <iterator>
using namespace std;

int main(int ac, char* av[])
{
    try {

        po::options_description desc("Allowed options");
        desc.add_options()
            ("help,h", "produce help message")
            ("compression", po::value<double>(), "set compression level")
			("include-path,I", po::value<std::string>(), "set path")
			("debugflag,D", po::value<bool>(), "set file")
        ;

        po::variables_map vm;        
        po::store(po::parse_command_line(ac, av, desc), vm);
        po::notify(vm);

        if (vm.count("help")) {
            cout << desc << "\n";
            //return 0;
        }

        if (vm.count("compression")) {
            cout << "Compression level was set to " 
                 << vm["compression"].as<double>() << ".\n";
        } else {
            cout << "Compression level was not set.\n";
        }

		if (vm.count("include-path")) {
			cout << "include-path are :  " 
				<< vm["include-path"].as<std::string>() << ".\n";
		} else {
			cout << "include-path  was not set.\n";
		}


		if (vm.count("debugflag")) {
			cout << "debugflag are : " 
				<< vm["debugflag"].as<bool>() << ".\n";
		} else {
			cout << "debugflag was not set.\n";
		}
    }
    catch(exception& e) {
        cerr << "error: " << e.what() << "\n";
        return 1;
    }
    catch(...) {
        cerr << "Exception of unknown type!\n";
    }

    return 0;
}

上面程序加上如下参数运行：

testDemo --help --compression 12 -I ssssss -D true

结果：

Allowed options:
  -h [ --help ]             produce help message
  --compression arg         set compression level
  -I [ --include-path ] arg set path
  -D [ --debugflag ] arg    set file


Compression level was set to 12.
include-path are :  ssssss.
debugflag are : 1.