Creating a simple configuration file and parser in C++

Question

I am trying to create a simple configuration file that looks like this

url = http://mysite.com
file = main.exe
true = 0

when the program ru

Answer 1

As others have pointed out, it will probably be less work to make use of an existing configuration-file parser library rather than re-invent the wheel.

For example, if you decide to use the Config4Cpp library (which I maintain), then your configuration file syntax will be slightly different (put double quotes around values and terminate assignment statements with a semicolon) as shown in the example below:

# File: someFile.cfg
url = "http://mysite.com";
file = "main.exe";
true_false = "true";

The following program parses the above configuration file, copies the desired values into variables and prints them:

#include 
#include 
using namespace config4cpp;
using namespace std;

int main(int argc, char ** argv)
{
    Configuration *  cfg = Configuration::create();
    const char *     scope = "";
    const char *     configFile = "someFile.cfg";
    const char *     url;
    const char *     file;
    bool             true_false;

    try {
        cfg->parse(configFile);
        url        = cfg->lookupString(scope, "url");
        file       = cfg->lookupString(scope, "file");
        true_false = cfg->lookupBoolean(scope, "true_false");
    } catch(const ConfigurationException & ex) {
        cerr << ex.c_str() << endl;
        cfg->destroy();
        return 1;
    }
    cout << "url=" << url << "; file=" << file
         << "; true_false=" << true_false
         << endl;
    cfg->destroy();
    return 0;
}

The Config4Cpp website provides comprehensive documentation, but reading just Chapters 2 and 3 of the "Getting Started Guide" should be more than sufficient for your needs.