思路

ini文件是一种系统配置文件，它有特定的格式组成。通常做法，我们读取ini文件并按照ini格式进行解析即可。在c++语言中，提供了模板类的功能，所以我们可以提供一个更通用的模板类来解析ini文件。c++中和键值对最贴切的就是STL中的map了。所以我使用map作为properties的实际内存存储，同时为了方便使用，另外多一个set类型的字段记录所有的key。大致流程为：

1、逐行扫描文件内容；
2、过滤注释（#后面的为注释）；
3、根据等号切割key和value；
4、保存section,key和value到文件中；

需求：

1、当key没有值时：可以设定个默认值
2、读取文件时只有KEY没哟默认值会报错，添加一个默认值给该KEY
3、修改KEY的值时并保存到文件中，形成固定格式

ini.h

/********************************************************************************* @file           : ini.h* @author         : CircleDBA* @mail           : weiyuanquan@kingbase.com.cn* @blog           : circle-dba.blog.csdn.net* @date           : 24-5-8*******************************************************************************/#ifndef KINGBASEMANAGERTOOLS_INI_H
#define KINGBASEMANAGERTOOLS_INI_H#include <iostream>
#include <fstream>
#include <sstream>
#include <map>
#include <string>#include <set>
#include <filesystem>#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>
#include <boost/filesystem.hpp>using namespace std;namespace Circle {class ini {protected:string config_path;set<string>* keys = nullptr;map<string, string>* props = nullptr;void trim(string& s);vector<string> split(const string& str, char pattern);private:public:ini();virtual ~ini();void file(boost::filesystem::path path);bool is_exists();bool load(std::string defaultValue);bool load(){return load("None");};set<string>* getKeys() const;map<std::string, string> *const getProps() const;string getValue(const string& key,const string& defaultValue);string setValue(const string& key,const string& Value);bool save();};} // Circle#endif //KINGBASEMANAGERTOOLS_INI_H

ini.cpp

/********************************************************************************* @file           : ini.cpp* @author         : CircleDBA* @mail           : weiyuanquan@kingbase.com.cn* @blog           : circle-dba.blog.csdn.net* @date           : 24-5-8*******************************************************************************/#include "ini.h"namespace fs = boost::filesystem;namespace Circle {Circle::ini::ini() {this->props = new map<string, string>;this->keys = new set<string>();}Circle::ini::~ini() {delete props;delete keys;}void Circle::ini::file(boost::filesystem::path path){this->config_path = path.string();}bool Circle::ini::is_exists(){return fs::exists(this->config_path);}void Circle::ini::trim(string& s){if (!s.empty()){s.erase(0, s.find_first_not_of(" "));s.erase(s.find_last_not_of(" ") + 1);}}vector<string> Circle::ini::split(const string& str, char pattern){vector<string> res;stringstream input(str);string temp;while (getline(input, temp, pattern)){res.push_back(temp);}return res;}bool Circle::ini::load(std::string defaultValue = "None"){std::ifstream file(this->config_path);std::string line, key, value, section;while (getline(file, line)) {trim(line);//去空行if (line.empty() || line == "\r" || line[0] == '#'){continue;}int s_startpos, s_endpos;if (((s_startpos = line.find("[")) != -1) && ((s_endpos = line.find("]"))) != -1){section = line.substr(s_startpos + 1, s_endpos - 1);continue;}//处理等号后为空的配置vector<string> res = split(line, '=');if (res.size() < 2){res[1] = defaultValue;}int t = res[1].find("#");if (t != string::npos) {res[1].erase(t);}for_each(res.begin(), res.end(), [=](string& s)mutable {trim(s);});props->insert(make_pair(section+"."+res[0],res[1]));keys->insert(section);}file.close();return true;}set<string>* Circle::ini::getKeys() const {return keys;}map<std::string, string> *const Circle::ini::getProps() const {return this->props;}string Circle::ini::getValue(const string& key,const string& defaultValue) {if (props->find(key) == props->end()){return defaultValue;}string value = this->props->at(key);return value;}string Circle::ini::setValue(const string& key,const string& Value) {if (props->find(key) == props->end()){this->props->insert(make_pair(key, Value));}else{props->at(key) = Value;}return this->props->at(key);}bool Circle::ini::save(){std::ofstream outFile(this->config_path);set<string>* keysMap = getKeys();for (std::set<string>::const_iterator it = keysMap->begin(); it != keysMap->end(); ++it) {outFile << "[" << *it << "]" << std::endl;for (const auto &pair: *props) {vector<string> res = split(pair.first,'.');if(res[0] == *it){outFile << res[1] << " = " << pair.second << std::endl;}};}return true;}
} // Circle

config.conf

[group1]
IP = 192.168.30.1
name = group1
port = 7000
[group2]
IP = 192.168.1.101
name = group2
port = 7002

mian.cpp

/********************************************************************************* @file           : Application.h* @author         : CircleDBA* @mail           : weiyuanquan@kingbase.com.cn* @blog           : circle-dba.blog.csdn.net* @date           : 24-5-6*******************************************************************************/#ifndef KINGBASEMANAGERTOOLS_APPLICATION_H
#define KINGBASEMANAGERTOOLS_APPLICATION_H
#include <iostream>
#include <boost/filesystem.hpp>
#include "src/path/path.h"
#include "src/config/ini.h"namespace Circle {class Application {protected:private:public:boost::filesystem::path RootPath,ConfigPath,DefaultConfigPath;Circle::path* Path;Application() {RootPath = Path->ApplictionPath();ConfigPath = RootPath / "config";DefaultConfigPath = RootPath  / "include" / "Application" / "config";boost::filesystem::path config = DefaultConfigPath / "config.conf";std::cout << "--------------------------------> start" << std::endl;Circle::ini ini;ini.file(config);if(ini.is_exists()){ini.load();std::cout << ini.getValue("group1.IP","192.168.30.1") << std::endl;std::cout << ini.setValue("group1.IP","192.168.30.1") << std::endl;ini.save();std::cout << "-------------------------------->for start" << std::endl;map<string, string>* dataMap = ini.getProps();for (const auto &pair : *dataMap) {std::cout << pair.first << "=>" << pair.second <<std::endl;};}std::cout << "--------------------------------> end" << std::endl;}};} // Application#endif //KINGBASEMANAGERTOOLS_APPLICATION_H