Question

sorry in advance for the formatting. Couldn’t figure it out…

I’m passing a config file to a program via arguments

I’m trying to read a value from a specific parameter

I’ve got a cofigReader class with the following method for returning a string from a config file given a specific parameter

My problem,

it never finds the parameter. found is either 0 or -1….

string configReader::value(string config_file, string parameter)
{
    string value;
    char config_delimiter = '=';
    size_t found;
    file.open(config_file);
    std::string line;
    bool param_found = false;
    while(param_found == false){
        while (!file.eof())
        {       
            getline(file,line);
            logger.writetolog("INFO","Looking for " + parameter +
                         " on line "+ line); 
            found = line.find(parameter);
            logger.writetolog("INFO",int(found));
            if(found!=string::npos){
                param_found = true;
            }
        }
        param_found = true;
    }
    if (found!=string::npos)
    {   
        size_t a = line.find(config_delimiter)+1;
        logger.writetolog("INFO","Found" + parameter + 
                   "splitting string at delimter" + config_delimiter + 
                   " and return right side value");     
        value = line.substr(a);
        return value;
    }
    else
    {
        return value;
    }
    file.close();
}

more info. Config file reads like this.

toemail=[e-mail]
outputdir=C:\tmp

configReader class used like this

//attempt to parse out the required parameters for the program
string toemail = config.value(configFileArg,"toemail"); 

it ALWAYS return empty

Answer 1

Your while (!file.eof()) loop continues after you find a match, over-writing the value of found which you check later.

You could fix this by changing your loop to something like

bool param_found = false;
while (!param_found && !file.eof()) {       
    if (getline(file,line)) {
        break;
    }
    logger.writetolog("INFO","Looking for " + parameter +" on line "+ line); 
    found = line.find(parameter);
    logger.writetolog("INFO",int(found));
    if(found!=string::npos){
        param_found = true;
        break;
    }
}

instead. (Notice that this code removes your while(param_found == false) loop. As sftrabbit points out, that loop is unnecessary.)