How to bypass commented lines in external text file using ifstream in C++

Question

I'm having trouble filtering the 'commented' lines in a text file. I want to filter the lines beginning with # or // in the text file.

Thanks!

string code, name, year, semester, value, data;

char delimiter = '|';

ifstream ifsUnits;
ifsUnits.open("./data/units.txt");

if (ifsUnits.fail())
    cout << "\nError reading from file <units.txt>.";
else
{
    while (!ifsUnits.eof())
    {
        getline(ifsUnits, data);
        stringstream ssData(data);
        while (ssData.good())
        {
            getline(ssData, code, delimiter);
            getline(ssData, name, delimiter);
            getline(ssData, year, delimiter);
            getline(ssData, semester, delimiter);
            getline(ssData, value, delimiter);

            lUnits.push_back(Unit(stoi(code), name, stoi(year), stoi(semester), stoi(value)));
        }
    }
}
ifsUnits.close();

Text file contents:

//idNumber|name <-- i want to bypass all the lines starting with // 1001|Mary Doe 1002|John Down 1003|John Doe 1004|Marilyn Hendrix

Answer 1

You're already pulling one line into a string at a time. Just check if that string starts with your comment characters and if so, continue:

while (getline(ifsUnits, data)) // more robust than eof check
{
    if ((data.size() > 1 && data[0] == '/' && data[1] == '/')
        || (data.size() > 0 && data[0] == '#')) { continue; }
    
    stringstream ssData(data);
    // ...