CODEWITHSUNDEEP
c++
KeyHeart
KeyHeart

Reputation: 173

More efficient way to read from file and set variables?

Is there a better way for me to read values from a file and set them accordingly? Could I somehow read a variable name from the file and set it accordingly in the program? For example, read BitDepth and set it to the value stated in the file? Therefore, I don't have to check if this line is BitDepth then set bit_depth to that value that follows?

std::ifstream config (exec_path + "/Data/config.ini");
if (!config.good ()) SetStatus (EXIT_FAILURE);
while (!config.eof ()) {
    std::string tmp;
    std::getline (config, tmp);
    if (tmp.find ("=") != 1) {
        if (!tmp.substr (0, tmp.find (" ")).compare ("BitDepth")) {
            tmp = tmp.substr (tmp.find_last_of (" ") + 1, tmp.length ());
            bit_depth = atoi (tmp.c_str ());
        } else if (!tmp.substr (0, tmp.find (" ")).compare ("WindowWidth")) {
            tmp = tmp.substr (tmp.find_last_of (" ") + 1, tmp.length ());
            screen_width = atoi (tmp.c_str ());
        } else if (!tmp.substr (0, tmp.find (" ")).compare ("WindowHeight")) {
            tmp = tmp.substr (tmp.find_last_of (" ") + 1, tmp.length ());
            screen_height = atoi (tmp.c_str ());
        }
    }
}

config.ini

[Display]
BitDepth = 32
WindowWidth = 853
WindowHeight = 480

Upvotes: 0

Views: 119

Answers (1)

LihO
LihO

Reputation: 42133

You could use std::map to make this approach more flexible. Also note that instead of checking the erturn value of config.eof() it is much better to check the return value of std::getline directly:

std::map<std::string, int> myConfig;

std::string line, key, delim;
while (std::getline(config, line))
{
    // skip empty lines:
    if (line.empty()) continue;

    // construct stream and extract tokens from it:
    std::string key, delim;
    int val;
    if (!(std::istringstream(line) >> key >> delim >> val) || delim != "=")
        break; // TODO: reading from the config failed 

    // store the new key-value config record:
    myConfig[key] = val;
}

It's up to you how you deal with the situation when the parsing of one of the config lines fails :)

Upvotes: 3

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