boost之program_options库，解析命令行参数、读取配置文件

原文链接:
​http://www.cnblogs.com/lidabo/p/3906053.html
​​
​一、命令行解析

tprogram_options解析命令行参数示例代码：

 

 #include <iostream>
 using namespace std;

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

 int main(int argc, char*argv[])
 {
     //int level;
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "produce help message")
         //("help,h", "produce help message")
         ("compression", po::value<int>(), "set compression level");
         //("compression", po::value<int>(&level)->default_value(1), "set compression level");

     po::variables_map vm;
     po::store(po::parse_command_line(argc, argv, desc), vm);
     po::notify(vm);

     if(vm.count("help"))
     {
         cout<<desc<<endl;
         return 1;
     }

     if(vm.count("compression"))
     {
         cout<<"compression level was set to "<<vm["compression"].as<int>()<<"."<<endl;
         //cout<<"compression level: "<<level<<endl;
     }
     else
     {
         cout<<"compression level was not set."<<endl;
     }

     return 0;
 }

 

运行结果：

 

输入参数：--help

 

输入参数：--compression 10

 

二、读取配置文件（Linux、Windows均可）

2.1 代码

 

 #include <fstream>
 #include <map>
 using namespace std;

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

 #ifdef WIN32
 #include "C:\Users\gwy8868\Desktop\fast_dr302\fast_dr302\global\xtokens.h"
 #else
 #include "/opt/guowenyan/fast_dr302/global/xtokens.h"
 #endif


 std::pair<std::string, std::string> at_option_parser(std::string const& s)
 {
     if ('@' == s[0])
     {
         return make_pair(std::string("config"), s.substr(1));
     }
     else
     {
         return std::pair<std::string, std::string>();
     }
 }

 int main(int argc, char*argv[])
 {
     //
     string host_ip;
     short  host_port;

     string server_ip;
     short  server_port;

     //
     po::options_description hostoptions("host options");
     hostoptions.add_options()
         ("host_ip,H", po::value<string>(&host_ip), "set db_host")
         ("host_port,P", po::value<short>(&host_port)->default_value(3306), "set db_port");

     po::options_description general("general options");
     general.add_options()
         ("help,h", "produce help message")
         ("server_ip,s", po::value<string>(&server_ip), "set the http_server's ip. e.g. '202.106.0.20'")
         ("server_port,p", po::value<short>(&server_port)->default_value(80), "set the http_server's port. default:80");

     string config_file;
     po::options_description config("config options");
     config.add_options()
         ("config", po::value<string>(&config_file)->default_value("config.conf"),
         "set config file, specified with '@name' too");

     po::options_description all("All options");
     all.add(hostoptions).add(general).add(config);

     po::variables_map vm;
     po::store(po::command_line_parser(argc, argv).options(all).extra_parser(::at_option_parser).run(), vm);

     if (vm.count("help"))
     {
         cout << hostoptions <<endl;
         cout << general << endl;
         cout << config << endl;
         return false;
     }

     if (vm.count("config"))
     {
         string conf_name = vm["config"].as<string>();
         ifstream ifs_config(conf_name.c_str());

         if (! ifs_config)
         {
             cerr << "could not open the configure file" << endl;
             return false;
         }

         stringstream ss_config;
         ss_config << ifs_config.rdbuf();

         global::strings_t args;
         global::separate_tokens(ss_config.str(), args, " \r\n");
         po::store(po::command_line_parser(args).options(all).run(), vm);
     }
     po::notify(vm);


     //
     cout<<"host_ip: "<<host_ip<<endl;
     cout<<"host_port: "<<host_port<<endl;

     cout<<"server_ip: "<<server_ip<<endl;
     cout<<"server_port: "<<server_port<<endl;

     return 0;
 }

2.2 配置文件

 

config.conf：

config2.conf：

2.3 输出结果