program_options读命令行和配置文件

#include <boost/program_options.hpp>
#include <string.h>
#include <iostream>
#include <fstream>
#include <map>

using namespace std;
using namespace boost;

namespace bpo = boost::program_options;

/*
config.ini:
p2p-endpoint = 0.0.0.1:31010

rpc-endpoint = 0.0.0.0:38090

*/
int main(int argc,char** argv)
{
    cout << "cmd line:" << endl;
    bpo::options_description desc("Allowed options");
    desc.add_options()
            ("help", "produce help message")
            ("df_value", bpo::value<string>()->default_value("123"), ""); //give default

    bpo::variables_map cmdValueMap;
    bpo::store(bpo::parse_command_line(argc, argv, desc), cmdValueMap);
    bpo::notify(cmdValueMap);

    if(cmdValueMap.count("help")){
        cout<<desc<<endl;
    }
    if(cmdValueMap.count("df_value")){
        cout << "df_value:" << cmdValueMap["df_value"].as<string>() << endl;
    }

    cout << endl;
    cout << "直接读取文件配置:" << endl;
    boost::program_options::options_description options("Graphene Witness Node");
    bpo::variables_map fileValueMap;
    options.add_options()
             ("p2p-endpoint", bpo::value<string>(), "Endpoint for P2P node to listen on")
             ("rpc-endpoint", bpo::value<string>(),"aaa")
             ("genesis-json", bpo::value<string>()->default_value("my-genesis.json"),"genesis-json");

    bool useIfStream = true;//both is ok
    if(useIfStream)
    {
        ifstream ifs("config.ini");
        boost::program_options::store(boost::program_options::parse_config_file(ifs,options), fileValueMap);
    }else
    {
        boost::program_options::store(boost::program_options::parse_config_file<char>("config.ini",options, true), fileValueMap);
    }
    boost::program_options::notify(fileValueMap);

    if(fileValueMap.count("p2p-endpoint")){
        cout << fileValueMap["p2p-endpoint"].as<string>() << endl;
    }
    if(fileValueMap.count("rpc-endpoint")){
        cout << fileValueMap["rpc-endpoint"].as<string>() << endl;
    }
    if(fileValueMap.count("genesis-json")){
        cout << fileValueMap["genesis-json"].as<string>() << endl;
    }

    cout << endl;
    cout << "遍历valueMap:" << endl;
    for(bpo::variables_map::iterator iter = fileValueMap.begin(); iter != fileValueMap.end(); ++iter){
        cout << iter->first << ":" << iter->second.as<string>() << endl;
    }
}




执行:./a.out --help

cmd line:
Allowed options:
  --help                produce help message
  --df_value arg (=123)

df_value:123

直接读取文件配置:
0.0.0.1:31010
0.0.0.0:38090
my-genesis.json

遍历valueMap:
genesis-json:my-genesis.json
p2p-endpoint:0.0.0.1:31010
rpc-endpoint:0.0.0.0:38090