C++ getline() after clear() - c++

Question

First, I'm sorry but I don't speak english very well.
My problem is that I want my stream go back begining of the file. So, i apply the clear() method upon my stream object, but after this, getline() always return 0 (false).
I don't find the solution. Somebody has an idea about this problem?
So, this is my code:
void Tools::tokenizeAll(string filename, string separator){
char str[LINESIZE] = {0};
int lineNumber = 0, j = 0;
ifstream stream;
stream.open(filename.c_str(), std::ifstream::in);
if(stream){
while(stream.getline(str, LINESIZE)){
lineNumber++;
}
//allocation dynamique du tableau à deux dimensions
string** elementsTable = NULL;
elementsTable = new string*[lineNumber];
for( int i = 0 ; i < lineNumber ; i++ ) elementsTable[i] = new string[4];
std::cout << " good()=" << stream.good() << endl;
std::cout << " eof()=" << stream.eof() << endl;
std::cout << " fail()=" << stream.fail() << endl;
std::cout << " bad()=" << stream.bad() << endl;
cout << endl;
stream.clear();
std::cout << " good()=" << stream.good() << endl;
std::cout << " eof()=" << stream.eof() << endl;
std::cout << " fail()=" << stream.fail() << endl;
std::cout << " bad()=" << stream.bad() << endl;
cout << endl;
cout << stream.getline(str, LINESIZE) << endl;//return 0
}
else cout << "ERREUR: Impossible d'ouvrir le fichier en lecture." << endl;
}
Thank you very much (and thank you to warn me about my english errors ;) )

Answer 1

Calling clear() only resets the error flags. To "rewind" the stream to the beginning, you'll also need to use seekg:
stream.seekg(0, std::ios::beg)
Note that this operation can fail, too, so you might want to check for errors.