Question

so I was trying to utilise the istringstream to parse through a text file. The idea is to break down each line by space and based on the substring do stuff. The code works fine except for two things, it double counts last substring for each line and it seg faults when its done reading through the file. I have not used sstream before so any insight would be helpful.

file.getline(str,80);

    while(!file.eof())

    {

        cout<<str<<endl;
        istringstream iss(str);
        while (iss)
            {
                iss >> sstr;
                cout << "Substring: " <<sstr << endl;
         }
        file.getline(str,80);   
    }

Answer 1

The while loops should go like this:

std::string line;

while (std::getline(file, line))
{
    std::istringstream iss(line);
    std::string token;

    while (iss >> token)
    {
        cout << "Substring: " << token << endl;
    }
}

The getline and input operations return the stream object, which itself has a specialized conversion to bool that indicates whether the operation succeeded, and it will fail precisely when you’ve reached the end of the respective stream.