Reading in a specific column of data from a text file in C

Question

My text file looks like this:

987 10.50   N   50
383 9.500   N   20
224 12.00   N   40

I want to read only the second column of data. How w

Answer 1

In C++ you could consider using std::istringstream, which requires the include: #include . Something like:

std::ifstream ifs("mydatafile.txt");

std::string line;

while(std::getline(ifs, line)) // read one line from ifs
{
    std::istringstream iss(line); // access line as a stream

    // we only need the first two columns
    int column1;
    float column2;

    iss >> column1 >> column2; // no need to read further

    // do what you will with column2
}

What std::istringstream does is allow you to treat a std::string like an input stream just like a regular file.

The you can use iss >> column1 >> column2 which reads the column data into the vaiables.