libconfig++(http://www.hyperrealm.com/libconfig/)是一个用于处理结构化配置文件的简单库。libconfig++的配置的文件格式非常简洁，可读性也非常的好，而且是type-aware，普通的配置文件读取后存取的类型为字符串，libconfig++可以“识别”整形的配置。libconfig++的配置形式也非常的灵活。此外，libconfig++还可以修改配置文件。
安装
安装包：libconfig-1.5.tar.gz安装过程：解压，配置，编译，安装//解压安装包tar -zxvf libconfig-1.5.tar.gz //安装前的引导配置，默认安装到/usr/local，可以通过./configure --PRefix=PREFIX进行修改，也可以修改脚本参数ac_default_prefix的值cd libconfig-1.5; ./configure //编译源码make//安装前的检查make check//安装make install使用说明 所需头文件libconfig.h++，编译时需要链接动态库libconfig++
class LIBCONFIGXX_API Config{public: Config(); //默认构造函数 virtual ~Config(); //析构函数 ... void read(FILE *stream); //以文件流的方式读取配置 void write(FILE *stream) const;//以文件流的方式修改配置 void readFile(const char *filename); //读取指定文件名的配置 void writeFile(const char *filename);//修改指定文件名的配置 Setting & lookup(const char *path) const; // inline Setting & lookup(const std::string &path) const { return(lookup(path.c_str())); } bool exists(const char *path) const; //判断是否存在某项配置名 inline bool exists(const std::string &path) const { return(exists(path.c_str())); } //查找指定节点的值 bool lookupValue(const char *path, bool &value) const; bool lookupValue(const char *path, int &value) const; bool lookupValue(const char *path, unsigned int &value) const; ... Setting & getRoot() const;//获取配置的根节点 ...private: ... config_t *_config; Setting::Format _defaultFormat; //禁止拷贝和赋值 Config(const Config& other); // not supported Config& Operator=(const Config& other); // not supported};//获取/修改配置class LIBCONFIGXX_API Setting{friend class Config;...public: virtual ~Setting(); inline Type getType() const { return(_type); } Setting & lookup(const char *path) const; inline Setting & lookup(const std::string &path) const { return(lookup(path.c_str())); } Setting & operator[](const char *name) const; Setting & operator[](int index) const; //从readFile的结果中查找path的值，并将其赋给指定的类型vlaue bool lookupValue(const char *name, bool &value) const; bool lookupValue(const char *name, int &value) const; bool lookupValue(const char *name, unsigned int &value) const; bool lookupValue(const char *name, long long &value) const; bool lookupValue(const char *name, unsigned long long &value) const; ... //用于添加指定类型的节点 Setting & add(const char *name, Type type); inline Setting & add(const std::string &name, Type type) { return(add(name.c_str(), type)); } Setting & add(Type type); bool exists(const char *name) const; //判断某项配置是否存在 inline bool exists(const std::string &name) const { return(exists(name.c_str())); } ...private: config_setting_t *_setting; ... Setting(const Setting& other); // not supported Setting& operator=(const Setting& other); // not supported};//其他相关迭代器class SettingIterator;class SettingConstIterator;各种异常捕获类class SettingTypeException;class SettingNotFoundException;class SettingNameException;class FileIOException;class ParseException;示例代码 下面给出示例代码，代码中先对配置文件进行读取，最后进行修改，涉及常用的各种类型。
#include <iostream>#include <string>#include <vector>#include <map>#include "libconfig.h++"using namespace std;int main(){ libconfig::Config mConfig; string strConfPath = "./example.cfg"; //解读配置文件 try { mConfig.readFile(strConfPath.c_str()); } catch(libconfig::FileIOException &e) { cout<<"read file [ "<<strConfPath<< " ] FileIOException"<<endl; return -1; } catch(libconfig::ParseException &e) { cout<<"read file [ "<<strConfPath<< " ],ParaseException: "<<e.getError()<<",line:"<<e.getLine()<<endl; return -1; } catch(...) { cout<<"read file ["<<strConfPath<< " ] unknown exception"<<endl; return -1; } //int try { int num = mConfig.lookup("NUMBER"); cout<<"Number:"<<num<<endl; } catch(...) { cout<<"Get Number from "<<strConfPath<<" failed ..."<<endl; } //string try { string str = mConfig.lookup("STRING"); cout<<"String:"<<str<<endl; } catch(...) { cout<<"Get String from "<<strConfPath<<" failed ..."<<endl; } //Array try { const libconfig::Setting &root = mConfig.getRoot(); const libconfig::Setting &arr = root["ARRAY"]; int cnt = arr.getLength(); vector<string> vs; for(int i = 0 ; i < cnt ;++i) { string tmp = arr[i]; vs.push_back(tmp); cout<<"Array["<<i<<"]:"<<tmp<<endl; } } catch(...) { cout<<"Get Array from "<<strConfPath<<" failed ..."<<endl; } //Map try { const libconfig::Setting &root = mConfig.getRoot(); const libconfig::Setting &maps = root["MAP"]; int cnt = maps.getLength(); int key; string value; map<int,string> mi; for(int i = 0 ; i < cnt ;++i) { const libconfig::Setting &tmp = maps[i]; tmp.lookupValue("key",key); tmp.lookupValue("value",value); mi.insert(make_pair(key,value)); cout<<"Map["<<i<<"]:"<<key<<"->"<<value<<endl; } } catch(...) { cout<<"Get Map from "<<strConfPath<<" failed ..."<<endl; } libconfig::Setting &root = mConfig.getRoot(); //增加一行整数配置 root.add("aaa", libconfig::Setting::TypeInt)=95; //增加一行字符串配置 root.add("bbb", libconfig::Setting::TypeString)="add string"; //增加数组 libconfig::Setting &array = root.add("array", libconfig::Setting::TypeArray); for(int i = 0; i < 10; ++i) array.add(libconfig::Setting::TypeInt) = 10 * i; // Add some settings to the configuration. libconfig::Setting &address = root.add("address", libconfig::Setting::TypeGroup); address.add("city", libconfig::Setting::TypeString) = "Nanjing"; address.add("province", libconfig::Setting::TypeString) = "JS"; // Write out the new configuration. try { mConfig.writeFile(strConfPath.c_str()); cout << "New configuration successfully written to: " << strConfPath << endl; } catch( libconfig::FileIOException &fioex) { cerr << "I/O error while writing file: " << strConfPath << endl; return(-1); } return 0;}运行结果
[root@localhost linconfig]# g++ -g main.cpp -lconfig++ -o run[root@localhost linconfig]# ./runNumber:100String:hello worldArray[0]:appleArray[1]:bananaArray[2]:orangeMap[0]:100->hundredMap[1]:1000->thousandNew configuration successfully written to: ./example.cfg新增的配置会被写到example.cfg中本文对libconfig++做了简单的介绍，对于其中重要的几个类进行了概要的说明，然而给出了相关使用示例，示例涉及常用的操作，可以被应用到工程中。
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