I have an text file that stores the details of objects of an account class. I need to be able to search the text file based on what account number the user has entered. each account number is a 4 digit integer.
I have it working for the first line of a file but i dont know how I can move it on to search the start of the next line of the file. This is the code taht i have so far.

char card[5];
char c;
long int file_pos, last_pos;
string line;

cin >> card;

ifstream in("account.txt") ;

while (!in.eof())
{
getline(in, line);
cout <<line<<endl;
file_pos = line.find(card);
}

Any help would be appreciated. I have not been able to find a tutorial on the web to explain this to me.