testing-repository/cpp/cfgfile2.cpp

// A Test to read Config files
// This is a modified version
// The Config File Should be a text file 
// and the content as follows
// key=value

#include <iostream>
#include <fstream>
#include <string>
#include <map>

typedef void (*pfun)();//The Function Pointer
typedef std::map<std::string,std::string> conf_map;//Container of configs

void Trim(std::string &str){
    if(str.empty()){//String is empty
        return;
    }
    int i;
    size_t start_pos,end_pos;

    for(i=0;i<str.size();i++){//Get Start Position
        if(!isspace(str[i])){
            break;
        }
    }

    if(i==str.size()){//Only Space and Tabs in string
        return;
    }

    start_pos=i;

    for(i=str.size()-1;i>=0;i--){//Get End Position
        if(!isspace(str[i])){
            break;
        }
    }

    end_pos=i;

    str=str.substr(start_pos,end_pos+1);
}

bool readCfgFile(const char * cfgfilePath,conf_map &configs){
    //Open The Config File and load config to map
    std::fstream cfgfile;
    cfgfile.open(cfgfilePath);
    if(!cfgfile.is_open()){
        std::cout<<"Failed to open the file!"<<std::endl;
        return false;
    }

    //If Map is not empty,clear it
    if(!configs.empty()){
        configs.clear();
    }

    //Read each line of config file and get value
    char tmp[1000];
    while(!cfgfile.eof()){
        cfgfile.getline(tmp,1000);
        std::string line(tmp),value;
        std::size_t pos = line.find('=');//Get the position of '='

        if(pos == std::string::npos){//No Configs
            continue;
        }

        std::string key=line.substr(0,pos);
        value=line.substr(pos+1);

        //Clear Spaces
        Trim(key);Trim(value);

        configs[key]=value;
    }

    cfgfile.close();
    return true;
}

void readcfg(){
    //Input Config File Path and Key
    char filename[1000];
    std::string cfgkey;
    conf_map test_config;

    std::cout<<"Input Config File Name:";//Config File Name
    std::cin.get();//Clear the cin to read line
    std::cin.getline(filename,1000);

    std::cout<<"Input Config Key:";//Config Key
    std::cin>>cfgkey;

    //Get The Config
    if(readCfgFile(filename,test_config)){
        std::cout<<"The Config Of "<<cfgkey<<" is "<<test_config[cfgkey]<<std::endl;
    }else{
        std::cout<<"Failed to Read Config!"<<std::endl;
    }
}

void appendcfg(){
    //Input Config File Path and Key
    char filename[1000];
    std::string cfgkey,cfgvalue;

    std::cout<<"Input Config File Name:";
    std::cin.get();//Clear the cin to read line
    std::cin.getline(filename,1000);

    //Append Config
    std::fstream cfgfile;
    cfgfile.open(filename,std::ios_base::app);

    if(cfgfile.is_open()){
        std::cout<<"Input Config Key And Config Value:";
        std::cin>>cfgkey>>cfgvalue;
        cfgfile<<std::endl;
        cfgfile<<cfgkey<<"="<<cfgvalue;
        cfgfile.close();
    }else{
        std::cout<<"Config File Open Failed!"<<std::endl;
    }
}

void show_configs(){
    //Input Config File Path and Key
    char filename[1000];
    conf_map test_config;

    std::cout<<"Input Config File Name"<<std::endl;//Config File Name
    std::cin.get();//Clear the cin to read line
    std::cin.getline(filename,1000);

    //Get The Config and Show all Config in map
    if(readCfgFile(filename,test_config)){
        auto mite=test_config.begin();
        for(;mite!=test_config.end();mite++){
            std::cout<<mite->first<<"="<<mite->second<<std::endl;
        }
        
    }else{
        std::cout<<"Failed to Read Config!"<<std::endl;
    }
}

int main(int argc,char **argv){
    //Function Pointer to select mode
    pfun feature[]={readcfg,appendcfg,show_configs};
    //Get Selection and execute a mode
    int selection;
    std::cout<<"0.Read a Config 1.Append a Config 2.Show all Configs"<<std::endl<<"Selection a mode:";
    std::cin>>selection;
    feature[selection]();
    return 0;
}