C++ lee el archivo de configuración en formato ini

1. Antecedentes

ini es el formato de archivo de configuración de inicio del programa en los primeros años. Algunos parámetros predeterminados se pueden configurar en este archivo. El formato es:

;引号后面为注释
[group1]
name = group1
IP = 192.168.1.100
port = 7000
[group2]
name =  group2
IP = 192.168.1.101
port = 7002

[] Debajo de los corchetes hay una sección y el siguiente valor está indexado a través del nombre de la variable. 

2. Código

Incluyendo el siguiente archivo de encabezado, puede leer y analizar archivos en formato ini a través de esta clase

esto.h

#ifndef INI_H_
#define INI_H_
#include <string>
#include <map>
#include<fstream>

namespace ini
{
	class iniReader
	{
	public:
		iniReader()
		{
		}
		~iniReader()
		{
		}
		bool ReadConfig(const std::string & filename)
		{
			settings_.clear();
			std::ifstream infile(filename.c_str());//构造默认调用open,所以可以不调用open
			//std::ifstream infile;
			//infile.open(filename.c_str());
			//bool ret = infile.is_open()
			if (!infile) {
				return false;
			}
			std::string line, key, value, section;
			std::map<std::string, std::string> k_v;
			std::map<std::string, std::map<std::string, std::string> >::iterator it;
			while (getline(infile, line))
			{
				if (AnalyseLine(line, section, key, value))
				{
					it = settings_.find(section);
					if (it != settings_.end())
					{
						k_v[key] = value;
						it->second = k_v;
					}
					else
					{
						k_v.clear();
						settings_.insert(std::make_pair(section, k_v));
					}
				}
				key.clear();
				value.clear();
			}
			infile.close();
			return true;
		}

		std::string ReadString(const char* section, const char* item, const char* default_value)
		{
			std::string tmp_s(section);
			std::string tmp_i(item);
			std::string def(default_value);
			std::map<std::string, std::string> k_v;
			std::map<std::string, std::string>::iterator it_item;
			std::map<std::string, std::map<std::string, std::string> >::iterator it;
			it = settings_.find(tmp_s);
			if (it == settings_.end())
			{
				//printf("111");
				return def;
			}
			k_v = it->second;
			it_item = k_v.find(tmp_i);
			if (it_item == k_v.end())
			{
				//printf("222");
				return def;
			}
			return it_item->second;
		}

		int ReadInt(const char* section, const char* item, const int& default_value)
		{
			std::string tmp_s(section);
			std::string tmp_i(item);
			std::map<std::string, std::string> k_v;
			std::map<std::string, std::string>::iterator it_item;
			std::map<std::string, std::map<std::string, std::string> >::iterator it;
			it = settings_.find(tmp_s);
			if (it == settings_.end())
			{
				return default_value;
			}
			k_v = it->second;
			it_item = k_v.find(tmp_i);
			if (it_item == k_v.end())
			{
				return default_value;
			}
			return atoi(it_item->second.c_str());
		}

		float ReadFloat(const char* section, const char* item, const float& default_value)
		{
			std::string tmp_s(section);
			std::string tmp_i(item);
			std::map<std::string, std::string> k_v;
			std::map<std::string, std::string>::iterator it_item;
			std::map<std::string, std::map<std::string, std::string> >::iterator it;
			it = settings_.find(tmp_s);
			if (it == settings_.end())
			{
				return default_value;
			}
			k_v = it->second;
			it_item = k_v.find(tmp_i);
			if (it_item == k_v.end())
			{
				return default_value;
			}
			return atof(it_item->second.c_str());
		}

	private:
		bool IsSpace(char c)
		{
			if (' ' == c || '\t' == c)
				return true;
			return false;
		}
		
		bool IsCommentChar(char c)
		{
			switch (c) 
			{
			case '#':
				return true;
			default:
				return false;
			}
		}

		void Trim(std::string & str)
		{
			if (str.empty())
			{
				return;
			}
			int i, start_pos, end_pos;
			for (i = 0; i < str.size(); ++i) {
				if (!IsSpace(str[i])) {
					break;
				}
			}
			if (i == str.size())
			{
				str = "";
				return;
			}
			start_pos = i;
			for (i = str.size() - 1; i >= 0; --i) {
				if (!IsSpace(str[i])) {
					break;
				}
			}
			end_pos = i;
			str = str.substr(start_pos, end_pos - start_pos + 1);
		}

		bool AnalyseLine(const std::string & line, std::string& section, std::string & key, std::string & value)
		{
			if (line.empty())
				return false;
			int start_pos = 0, end_pos = line.size() - 1, pos, s_startpos, s_endpos;
			if ((pos = line.find("#")) != -1)
			{
				if (0 == pos)
				{
					return false;
				}
				end_pos = pos - 1;
			}
			if (((s_startpos = line.find("[")) != -1) && ((s_endpos = line.find("]"))) != -1)
			{
				section = line.substr(s_startpos + 1, s_endpos - 1);
				return true;
			}
			std::string new_line = line.substr(start_pos, start_pos + 1 - end_pos);
			if ((pos = new_line.find('=')) == -1)
				return false;
			key = new_line.substr(0, pos);
			value = new_line.substr(pos + 1, end_pos + 1 - (pos + 1));
			Trim(key);
			if (key.empty()) {
				return false;
			}
			Trim(value);
			if ((pos = value.find("\r")) > 0)
			{
				value.replace(pos, 1, "");
			}
			if ((pos = value.find("\n")) > 0)
			{
				value.replace(pos, 1, "");
			}
			return true;
		}

	private:
		//std::map<std::string, std::string> settings_;
		std::map<std::string, std::map<std::string, std::string> >settings_;
	};
}
#endif

 código de prueba

#include <iostream>
#include <fstream>
#include <cassert>
#include "ini.h"

int main() 
{

	ini::iniReader config;
	bool ret = config.ReadConfig("config.ini");
	if (ret == false) 
    {
		printf("ReadConfig is Error,Cfg=%s", "config.ini");
		return 1;
	}
	std::string HostName = config.ReadString("group1", "IP", "");
	int Port = config.ReadInt("group1", "port", 0);
	std::string UserName = config.ReadString("group1", "name", "");

	std::cout << "HostName=" << HostName << std::endl;
	std::cout << "Port=" << Port << std::endl;
	std::cout << "UserName=" << UserName << std::endl;

	return 0;
}