Help reading input file

I am trying to read an input file by inputing them directly into containers. This works up until the point where there is a new line and I have to go to the next. Here is the input file:

Code:

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P1 15 32 95 51
P2  99  5
P1 16 92 34 77 99
P2 Finish

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Ahead of time I dont know how many numbers will be following the P?. So far I loop through and grab each of the numbers with a line like this:

Code:

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file >> inputNum;

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When it runs out of numbers, inputNum becomes 0. Now I need to get to the next line and start with inputing a string "P2" and then start inputing integers again. How do I get to the next line? If I keep trying to input stuff it keeps giving me 0.

Here is my code reduced to show the important parts:

Code:

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while( !file.eof() )
    {
        file >> process;

        process[0] = '0';
       
        temp->process = atoi( process );

      while( inputNum != 0 )
      {
          file >> inputNum;

          if( inputNum < 1 )
          {
              break;
          }
           
    }

}

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I'm not eaxctly sure what you are doing, but one way
might be to read line by line into a string, put
the string into a stringstream, and process it.

Here is an example :

Code:

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#include <iostream>
#include <fstream>
#include <string>
#include <sstream>

using namespace std;

int main()
{
    ifstream file("lines.txt");
    if (!file)
    {
        cout << "problem with file open" << endl;
        return 0;
    }

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

        iss >> tag;

        cout << tag << endl;

        int value;
        while (iss >> value)
        {
            cout << "      " << value << endl;
        }
    }

    return 0;
}

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