Question

I am trying to convert date-times that i am receiving into a particular format to insert into a MySQL database. The program is written in C++, and the following solution works but I feel it is horribly inefficient.

The input is : Mon Nov 08 17:41:23 +0000 2010
The desired output format is: YYYY-MM-DD HH:MM:SS
So for this example the output would be: 2010-11-08 17:41:23

I have included the relevant parts of the code.

    //class variable
    std::map<std::string, std::string> monthMap;

void processor::initializeMonthMap(){
    monthMap["Jan"] = "01";
    monthMap["Feb"] = "02";
    monthMap["Mar"] = "03";
    monthMap["Apr"] = "04";
    monthMap["May"] = "05";
    monthMap["Jun"] = "06";
    monthMap["June"] = "06";
    monthMap["Jul"] = "07";
    monthMap["July"] = "07";
    monthMap["Aug"] = "08";
    monthMap["Sept"] = "09";
    monthMap["Sep"] = "09";
    monthMap["Oct"] = "10";
    monthMap["Nov"] = "11";
    monthMap["Dec"] = "12";
}

inline std::string processor::convertDate(std::string input) {
    //Format: Mon Nov 08 17:41:23 +0000 2010
    //To get to YYYY-MM-DD HH:MM:SS

    std::stringstream  newString(input);
    std::string temp1;
    std::string temp2;

    // Read Day in txt, discard
    newString >> temp1;

    //Read month, convert to number
    newString >> temp1;
    temp2 = "-" + monthMap[temp1] + "-";

    //Read Day in number
    newString >> temp1;
    temp2.append(temp1 + " ");

    //Read TimeStamp
    newString >> temp1;
    temp2.append(temp1);

    //Discard UTM adjustment
    newString >> temp1;

    //Read year
    newString >> temp1;

    //Add year to beginning of input
    temp1.append(temp2);

    return temp1;
}

Answer 1

You’re parsing the string and fortunately you can build the output by simple appends. I don’t see this getting more efficient.

However, it appears as if you can use seekg to position the cursor past day of the week and UTM adjustment.

http://www.cplusplus.com/reference/iostream/istream/seekg/